Resources > Bibliographical Database > Discussion about Fuzzy Sets QCA (fsQCA)

Discussion about Fuzzy Sets QCA (fsQCA)

  1. ACKRÉN, Maria (07.15.2006/07.16.2006), "A Summary of Comparing Comparisons: Territorial Autonomies in the Light of Alternative Methods", paper presented at : International Conference on Comparative Social Sciences, Tokyo, Japan,

  2. --------- (2010), "Conditions for Territorial Autonomies in the Light of QCA Techniques (CsQCA, MvQCA and FsQCA)", paper presented at : Paper, Abo Akademi University,
    Abstract: This article considers three various tools within the family of Qualitative Comparative Analysis (QCA). The techniques discussed are Crisp-Set QCA (or Boolean algebra), Multi-Value QCA and Fuzzy-Set QCA. All the tools will be highlighted and exemplified with empirical data derived from a forthcoming work about the degree and kind of territorial autonomies in the world.2 The idea is to show what happens when we use the different techniques for the same data set. This will show the usefulness and shortcomings, when combining various tools. The techniques are chosen, since they are all related to each other and therefore the similarities and differences between the three techniques are easier to grasp and the data set will not suffer, while we can obtain the same research question throughout the analyses. The assessment of QCA techniques gives us necessary and sufficient conditions according to set theoretical principles. Results show that csQCA and mvQCA give us uncertain results with a lot of contradictions between the cases, while fsQCA is more straightforward. FsQCA also gives us solution terms for the whole data set, which csQCA and mvQCA are lacking.

  3. ANONYMOUS (2003), Two-Level Theories and Fuzzy-Set Logic (unpublished manuscript).

  4. ______ (2010), An MCA of QCA (unpublished manuscript).

  5. ANONYMOUS (forthcoming), Causal Complexity and FS/QCA: Making Use of Remote and Proximate Causal Conditions (unpublished manuscript).

  6. ARFI, Badredine (9.2.2004/9.5.2004), "Complex Causality in Politics: A Linguistic Fuzzy-Logic Approach", paper presented at : APSA 2004 Annual Meeting, Chicago,

  7. ---------- (2005 (forthcoming)), "Fuzzy Decision Making in Politics: A Linguistic Fuzzy-Set Approach (LFSA)", Political Analysis,

  8. AYRTON, Robert (2002), Analyse en termes d'ensembles flous et son application dans l'étude des modes de mise en oeuvre cantonales de la LACI (unpublished manuscript).

  9. BALIAMOUNE-LUTZ, Mina (2004), "On the Measurement of Human Well-Being. Fuzzy Set Theory and Sen’s Capability Approach", WIDER , 16, 1-20.

  10. ---------- (2009), "Fuzzy Well-Being Achievement in Pacific Asia", SSRN Papers ,

  11. BENNETT, Andrew and ELMAN, Colin (Feb 2007), "Case Study Methods in the International Relations Subfield", Comparative Political Studies, 40, 2, 170-195.
    Abstract: This article reviews the key role that case study methods have played in the study of international relations (IR) in the United States. Case studies in the IR subfield are not the unconnected, atheoretical, and idiographic studies that their critics decry. IR case studies follow an increasingly standardized and rigorous set of prescriptions and have, together with statistical and formal work, contributed to cumulatively improving understandings of world politics. The article discusses and reviews examples of case selection criteria (including least likely, least and most similar, and deviant cases); conceptual innovation; typological theories, explanatory typologies, qualitative comparative analysis, and fuzzy-set analysis; process tracing; and the integration of multiple methods.

  12. BERG-SCHLOSSER, Dirk (2002), "Macro-Quantitative Vs Macro-Qualitative Methods in the Social Sciences - Testing Empirical Theories of Democracy", paper presented at : Colloque de la Revue Internationale de Politique Comparée "Faire de la politique comparée au 21eme siecle" Atelier 2:outils méthodologiques, Bordeaux, France,
    Abstract: There are some few attempts to bridge the divide between quantitative and qualitative methods in the social sciences. This paper explicitely illustrates and tests some of these methods like regression, cluster, or discriminant analysis, on the one hand, and more recent case- and diversity-oriented methods like QCA, Fuzzy Sets and similar ones, on the other. This is done by using examples and data for different empirical theories of democracy such as those by Lipset, Vanhanen, or Moore/Stephens. In this way, the specific strenghts and weaknesses of the respective methods and theories are demonstrated.

  13. ---------- (2002), "Macro-Quantitative Vs. Macro-Qualitative Methods in the Social Sciences. Testing Empirical Theories of Democracy", COMPASSS Working Paper, 2, 36p.
    Abstract: There are some new attempts to bridge the divide between quantitative and qualitative methods in the social sciences. My paper explicitely illustrates and tests some of these methods like regression, cluster, or discriminant analysis, on the one hand, and more recent case- and diversity-oriented methods like QCA, Fuzzy Sets and similar ones, on the other. This is done by using examples and data for different empirical theories of democracy such as those by Lipset, Vanhanen, or Moore/Stephens. In this way, the specific strengths and weakenesses of the respective methods and theories are demonstrated.

  14. BLATTER, Joachim and BLUME, Till (2008), "In Search of Co-Variance, Causal Mechanisms or Congruence? Towards a Plural Understanding of Case Studies", Swiss Political Science Review, 14, 2, 315-356.

  15. BOWMAN, Kirk, LEHOUCQ, Fabrice, and MAHONEY, James (2005), "Measuring Political Democracy. Case Expertise, Data Adequacy, and Central America", Comparative Political Studies, 38, 8, 939-970.
    Abstract: Recent writings concerning measurement of political democracy offer sophisticated discussions of problems of conceptualization, operationalization, and aggregation. Yet they have less to say about the error that derives from the use of inaccurate, partial, or misleading data sources. Drawing on evidence from five Central American countries, the authors show this data-induced measurement error compromises the validity of the principal, long-term cross-national scales of democracy. They call for an approach to index construction that relies on case expertise and use of a wide range of data sources, and they employ this approach in developing an index of political democracy for the Central American countries during the 20th century. The authors’index draws on a comprehensive set of secondary and primary sources as it rigorously pursues standards of conceptualization, operationalization, and aggregation. The index’s value is illustrated by showing how it suggests new lines of research in the field of Central American politics.

  16. CAT, Jordi (January 2006), "Fuzzy Empiricism and Fuzzy-Set Causality: What Is All the Fuzz About", Philosophy of Science, 73, 26-41.

  17. CHARFI, Mohamed (2010), Les facteurs de développement démocratique dans le monde arabe: analyse comparative configurationnelle, Genève, Université de Genève (unpublished).
    Abstract: This thesis uses a configurational comparative approach, to test the impact of different structural conditions on political regimes in 15 Arab countries. Two methods relatively new in democratisation studies on the region are applied: simple qualitative comparative analysis (crisp-set) and fuzzy sets. After a theoretical discussion, six factors are included in the analysis: economic crises, institutional structure, natural resources, monarchy, and basic socio-economic indicators (GDP and Education). The two methods employed emphasize the heterogeneity of causal explanations but the results of the fuzzy sets analysis are more accurate in terms of consistency and coverage. The final analysis reveals two major pathways leading to the "democratic opening / absolute authoritarianism" in Arab countries. Thus, countries characterised by enduring economic crises, fewer natural resources and low institutional capabilities are more likely to adopt liberal reforms. In contrast, countries with strong traditional tribal legitimacy, the corporate institutions and oil resources damping crisis effects, are more likely to persist in authoritarianism. This specific multi-causal explanation provides an original contribution to our understanding of the Arab regimes.

  18. CHIAPPERO-MARTINETTI, Enrica (2006), "Capability Approach and Fuzzy Set Theory: Description, Aggregation and Inference Issues", in LEMMI, A. and BETTI, G. (eds), Fuzzy Set Approach to Multidimensional Poverty MeasurementSpringer,

  19. CHIAPPERO-MARTINETTI, Enrica (2008), "Complexity and Vagueness in the Capability Approach: Strenght or Weekness?", in COMIM, Flavio, QIZILBASH, Mozaffar, and ALKIRE, Sabina (eds), The Capability Approach. Concepts, Measures and Applications , Cambridge, Cambridge University Press, pp. 268-309.

  20. COLLIER, David (1998), "Letter From the President. Comparative Method in the 1990s", APSA-CP. Newsletter of the APSA Organized Section in Comparative Politics, 9, 1, 1-4. (Online at : http://www.nd.edu/~apsacp/pdf/APSA-CP_Winter_1998.pdf)

  21. CRONQVIST, Lasse (9.18.2003/9.21.2003), "Extending the QCA Approach With Multi-Value Scales", paper presented at : 2nd ECPR General Conference, Section "Methodological Advances in Comparative Research : Concepts, Techniques, Applications", Panel "Assessing the Respective Potential of Qualitative Comparative Analysis (QCA), Fuzzy Sets and Other Techniques : Applications", Marburg, Germany,
    Abstract: QCA is increasingly receiving attention by social science researchers, but as the number of publications using the method rises, the main limitations of QCA, the necessity to use dichotomized variables and the deterministic algorithms of the QCA software, are being exposed. In my paper I want to present an extension of QCA with Multi-Value sets, allowing the researcher to use more finely graded scales with QCA instead of only using dichotomous sets. An introduction to MVQCA (Multi-Value QCA) is given, mainly the origin of MVQCA and the difference to QCA will be explained. The method will be demonstrated by comparing strictly dichotomous data set calculations with a multi value data set minimization. Then the range of data sets which are possible to deal with in QCA, MVQCA and FS/QCA will be discussed, including the possibility to abandon the deterministic nature of Boolean minimization by giving special attention to configurations almost only representing cases with identical outcomes, which could extend the use of (MV)QCA to more-than-small size Ns. Also some of the shortages of the Fuzzy Set approach will be mentioned (problematic probabilistic calculations, mixing fuzzy and non fuzzy variables).

  22. ---------- (2007c), Konfigurationelle Analyse mit Multi-Value QCA als Methode der Vergleichenden Politikwissenschaft mit einem Fallbeispiel aus der Vergleichenden Parteienforschung (Erfolg Grüner Parteien in den achtziger Jahren),University of Marburg (unpublished).

  23. CURCHOD, Corentin (2002), "Diversity-Oriented Research. Between Complexity and Generality", COMPASSS Working Paper, 4, 11p.
    Abstract: Warning This paper is NOT a working paper. This is a few notes I took while reading Charles Ragin's book on Fuzzy-Set (Ragin [2000]. "Fuzzy-Set Social Science", Chicago: The University of Chicago Press). I also selected a few quotations from the book, which seem useful to me. They appear in the text with a left borderline. Please do not quote this document, and check the original book before reusing quotations. Avertissement Ce papier N'EST PAS un working paper. Il s'agit de quelques notes prises pendant la lecture de l'ouvrage de Charles Ragin concernant les ensembles flous (Ragin [2000]. "Fuzzy-Set Social Science", Chicago: The University of Chicago Press). J'ai également sélectionné dans l'ouvrage quelques citations qui me semblaient utiles. Elles apparaissent dans le texte qui suit avec une bordure à gauche. Ne pas citer ce document, et vérifier l'ouvrage original avant de réutiliser les citations.

  24. DOWNEY, J. and STANYER, J. (Dec 2010), "Comparative Media Analysis: Why Some Fuzzy Thinking Might Help.Applying Fuzzy Set Qualitative Comparative Analysis to the Personalization of Mediated Political Communication", European Journal of Communication, 25, 4, 331-347.
    Abstract: This article examines the benefits of fuzzy set qualitative comparative analysis (fsQCA) for comparative media research. It shows the advantages of fuzzy set theoretic thinking in examining the causes of a major feature of contemporary political communication research, namely personalization. The article has three parts. The first is a critique of the method adopted by Hallin and Mancini, a generally laudable and highly influential recent contribution to comparative media analysis. The second is a brief introduction to fsQCA. The third demonstrates the method's usefulness by investigating the personalized character of mediated political communication.

  25. FS/QCA Rel. 9.62. Las Vegas.

  26. DRIDI, Chokri and HEWINGS, Geoffrey J. D. (2002), Sectors Associations and Similarities in Input-Output Systems: an Application of Dual Scaling and Fuzzy Logic to Canada and the United States, Discussion Papers, Regional Economics Applications Laboratory (REAL),
    Abstract: Understanding the linkages in an input-output system has been addressed by various methods, but many focused on the identification of key sectors in the economy. Sonis et al. (1996) offered as a field of influence theory an alternative approach focusing on analytical importance of elements and combinations of elements. The first objective of this paper is to offer a complementary approach to the field of influence and the so-called 'Matrioshka principal' (Sonis and Hewings, 1990); the adopted approach seeks hierarchial associations (i.e. statistical dependence) between supply and demand in input-output system. The second objective of this paper is to examine the cluster structure sales and purchases profiles when the principle of 'excluded middle' is violated by the use of fuzzy sets. Both approaches are based on the data analysis technique known as dual scaling (Nishisato, 1980, 1994). Results of this approach will be applied to input-output tables of the US and Canada.

  27. ELIASON, Scott R. and STRYKER, Robin (2009), "Goodness-of-Fit Tests and Descriptive Measures in Fuzzy-Set Analysis", Sociological Methods and Research , 38, 102-146.

  28. EMMENEGER, Patrick (2010), "Non-Events in Macro-Comparative Social Research: Why We Should Care and How We Can Analyze Them", COMPASSS Working Paper 2010-60, 2010-60,
    Abstract: This paper addresses the role of non-events in macro-comparative social research. Non-events are defined as critical junctures during which actors do not alter the policy path although the counterfactual case of policy change was a likely possibility. Macro-comparative researchers often overlook non-events. The reason for this is simple. Critical junctures are often identified on the basis of change that took place during these critical junctures. In contrast, there is no approach to identify critical junctures in the absence of change. Thus, although more or less explicit decisions to not change policy paths can be very informative, comparative researchers overlook these non-events because they do not realize that there were considerable possibilities for change during these critical junctures. In this paper, we discuss the role of non-events in macro-comparative social research. First, we explain how counterfactual theorizing can be used to integrate non-events in explanatory statements. Second, we demonstrate, using an example from our own research, how the consideration of non-events can advance our knowledge. Finally, we suggest a procedure, which can be used to analyze non-events and which is based on the combined usage of fsQCA to identify notconsistent cases, process tracing to determine the relevant critical junctures and disciplined counterfactual theorizing to probe whether change was really a possibility.

  29. FISHMAN, Daniel (2000), "Context-Specific Logic Models: Alternative Paths to Similar Outcomes", A Topical Interest Group of the American Evaluation Association,

  30. FISS, P. C. (Oct 2007), "A Set-Theoretic Approach to Organizational Configurations", Academy of Management Review, 32, 4, 1180-1198.
    Abstract: I argue that research on organizational configurations has been limited by a mismatch between theory and methods and introduce set-theoretic methods as a viable alternative for overcoming this mismatch. I demonstrate the value of such methods for studying organizational configurations and discuss their applicability for examining equifinality and limited diversity among configurations, as well as their relevance to other research fields such as complementarities theory, complexity theory, and the resource-based view.

  31. FISS, Peer C. (2011), "Building Better Causal Theories: A Fuzzy Set Approach to Typologies in Organization Research", Academy of Management Journal, 54, 393-420.

  32. FUHRMANN, Gy (1988), "Fuzziness of Concepts and Concepts of Fuzziness", Synthese, 75, 349-372.

  33. ---------- (1988), ""Prototypes" and "Fuzziness" in the Logic of Concepts", Synthese, 75, 317-347.

  34. GOERTZ, Gary (2003), "Assessing the Importance of Necessary or Sufficient Conditions in Fuzzy-Set Social Science", COMPASSS Working Paper, 7, 33p.
    Abstract: Political scientists of all stripes have proposed numerous necessary or sufficient condition hypotheses. For methodologists a question is then how can we assess the ``importance'' of these necessary conditions. This paper addresses two central questions about the importance of necessary or sufficient conditions. The first regards their ``absolute'' importance which is addressed via the concept of the trivialness of necessary or sufficient conditions. The second importance question deals with the relative importance of necessary or sufficient conditions: for example, if X_1 and X_2 are necessary or sufficient conditions, is one more important than the other? The paper develops measures to assess the importance of necessary or sufficient conditions in three related contexts: (1) Venn diagrams, (2) 2x2 tables, and (3) fuzzy logic, with an emphasis on fuzzy logic methods. The empirical analysis uses the measures of absolute and relative importance to extend Ragin's (2000) discussion of the causes of IMF riots.

  35. ---------- (9.2.2004/9.5.2004), "Assessing the Importance of Necessary or Sufficient Conditions in Fuzzy-Set Social Science", paper presented at : APSA 2004 Annual Meeting, Chicago,

  36. ---------- (2006), "Assessing the Trivialness, Relevance, and Relative Importance of Necessary and Sufficient Conditions in Social Science", Studies in Comparative International Development, 41, 2, 88-109.
    Abstract: Political scientists of all stripes have proposed numerous necessary or sufficient condition hypotheses. For methodologists a question is how can we assess tlie importance of these necessary cotiditions. This article addresses three central questions about the importance of necessary or sufficient conditions. The first concerns the "triviainess" of necessary or sufficient conditions. The second is how much a necessary or sufficient condition is "relevant?" The third important question deals with Ihe relative importance of necessary or sufficient conditions: for example, if A", and A', are necessary or sufTicient conditions., is one more important than the other? The article develops measures to assess the importance of necessary or sufficient conditions in three related contexts: (!) Venn diagrams, (2) 2 x 2 tables, and (3) fuzzy sets. Two empirical examples are discussed at length: (1) Skocpol's States and Social Revolutions: A Comparative Analysis of France. Russia, and China atid (2) Ragin's (2000) analysis of the causes of IMF riots.

  37. GOERTZ, Gary and MAHONEY, James (2003), "Two-Level Theories and Fuzzy Logic", COMPASSS Working Paper, 6, 32p.
    Abstract: Two-level theories explain outcomes with causal variables at two levels of analysis that are systematically related to one another. Although many prominent scholars in the field of comparative analysis have developed two-level theories, the empirical and methodological issues that these theories raise have yet to be investigated. In this article, we explore different structures of two-level theories and consider the issues involved in testing these theories with fuzzy-set methods. We show that grasping the overall structure of two-level theories requires both specifying the particular type of relationship (i.e., causal, ontological, or substitutable) that exists between and within levels of analysis and specifying the logical linkages between levels in terms of necessary and sufficient conditions. We argue that for the purposes of testing these theories fuzzy-set analysis provides a powerful set of tools. We illustrate this by doing an empirical, fuzzy-set of Skocpol's States and Social Revolutions. However, as the Skocpol example shows, fuzzy-set methods are not effective if the investigator fails to be clear about the two-level structure of these theories from the onset.

  38. ---------- (2004), "Two-Level Theories and Fuzzy Sets", COMPASSS Working Paper, 19, 30p.
    Abstract: Two-level theories explain outcomes with causal variables at two levels of analysis that are systematically related to one another. Although many prominent scholars in the field of comparative analysis have developed two-level theories, the empirical and methodological issues that these theories raise have yet to be investigated. In this article, we explore different structures of two-level theories and consider the issues involved in testing these theories with fuzzy-set methods. We show that grasping the overall structure of two-level theories requires both specifying the particular type of relationship (i.e., causal, ontological, or substitutable) that exists between and within levels of analysis and specifying the logical linkages between levels in terms of necessary and sufficient conditions. We argue that for the purposes of testing these theories fuzzy-set analysis provides a powerful set of tools. However, to realize this potential, investigators using fuzzy-set methods must be clear about the two-level structure of their theories from the onset. We illustrate these points through an empirical, fuzzy-set test of Skocpol’s States and Social Revolutions.

  39. HÄRKÖNEN, Juho and KOUVO, Antti (2002), "Kirja-arvio [A Book Review in Finnish]: Ragin, Charles C. 2000. Fuzzy-Set Social Science. University of Chicago Press, Chicago/London.", Sosiologia, 39, 2, 164-166.

  40. HERRMANN, A. M. and CRONQVIST, L. (2009), "When Dichotomisation Becomes a Problem for the Analysis of Middle-Sized Datasets", International Journal of Social Research Methodology, 12, 1, 33-50.
    Abstract: This article aims at illustrating the circumstances in which Qualitative Comparative Analysis (QCA) and its ramifications, fs/QCA and MVQCA, become particularly useful tools of analysis. To this end, we discuss the most pertinent problem which researchers encounter when using QCA: the problem of contradicting observations. In QCA analysis, contradictions arise from the sheer number of cases and the problem of dichotomisation. In order to handle contradictions, the method for analysing middle-sized-N situations should therefore be chosen according to two parameters: the size of a dataset, and the need to preserve raw-data information. While QCA is an apt tool for analysing comparatively small middle-sized datasets with a correspondingly reduced necessity to preserve cluster information, the opposite holds true for fs/QCA. MVQCA strikes a balance between these two methods as it is most suitable for analysing genuinely middle-sized case sets for which some cluster information needs to be preserved.

  41. HERRMANN, Andrea and CRONQVIST, Lasse (2005), "Fs/QCA and MVQCA: Different Answers to the Problem of Contradicting Observations in QCA", paper presented at : ECPR General Conference, Budapest, Hungary,
    Abstract: Abstract: This paper aims at illustrating under which circumstances QCA and its ramifications, fs/QCA and MVQCA, become particularly useful tools of analysis. To this end, we discuss the most pertinent problem which researchers encounter when using QCA, namely the problem of contradicting observations. In QCA analysis, contradictions arise from the sheer number of cases, as well as the problem of dichotomisation. Therefore, we argue that – in order to handle contradictions – the method for analysing middle-sized-N situations should be chosen according to two parameters: The size of a dataset on the one hand, and the need to preserve raw data information on the other. While QCA is a particularly adequate tool for analysing comparatively small middle-size datasets with a reduced necessity to preserve cluster information, the opposite holds true for fs/QCA. MVQCA, in turn, strikes a balance between these two methods as it is most suitable for analysing genuinely middle-size case-sets for which some cluster information needs to be preserved.

  42. HERRMANN, Andrea and CRONQVIST, Lasse (2006), "Contradictions in Qualitative Comparative Analysis (QCA): A Way Out of the Dilemma", EUI Working Paper SPS No. 2006/06,

  43. HOLLANDER, James F. (2002), "A Quick Look at Ragin's "Fuzzy Set Social Science"", Comparative & Historical Sociology, 14, 1, 7-9.

  44. HYYRYLÄINEN, Esa (9.5.2001/9.8.2001), "Linking Organizational Strategies With Staff Participation and Involvement Schemes: Theoritical and Methodological Considerations", paper presented at : EGPA Vaasa Conference, Vaasa, Finland. (www.soc.kuleuven.ac.be/pol/io/egpa/HRM/vaasa/Esa_Hyyrylainen_EGPA_paper.doc)

  45. HÄGE, Frank M. (2005), "Constructivism, Fuzzy Sets and (Very) Small-N: Revisiting the Conditions for Communicative Action", COMPASSS Working Paper, 33, 32p.
    Abstract:In this paper, it is argued that the fuzzy set approach can engage in a fruitful liaison with constructivist research. There are several important properties of fuzzy set analysis that overlap with constructivist theorizing and research practice. To demonstrate the usefulness of the approach, Niemann’s study on the conditions for communicative action is replicated and re-interpreted using fuzzy sets. The result is an improvement of the informational content, the precision and the validity of conclusions drawn from the empirical analysis. Furthermore, the re-interpretation points to theoretical and conceptual issues that need more consideration in future research.

  46. ISHIDA, Atsushi (2003), Fs/QCA No Tsukaikata. [How to Use Fs/QCA] (unpublished manuscript).

  47. KATZ, Aaron, VOM HAU, Matthias, and MAHONEY, James (2004), "Explaining the Great Reversal in Spanish America: Fuzzy-Set Methods Versus Statistical Methods", paper presented at : Annual Meeting of the American Political Science Association,

  48. KENT, Ray, "A Brief Guide and Workshop for Fuzzy-Set Qualitative Comparative Analysis", paper presented at : Systematic Mixed Methods Research Workshop, Manchester,

  49. KENT, Ray, "Empirical Approaches in the Use of Fuzzy Set Analysis", paper presented at : Expert Roundtable on the Study of Strategies of Social Change Using the Method of Qualitative Comparatvie Analysis (QCA), Manchester,

  50. KENT, Ray (2005), "Cases As Configurations: Using Combinatorial and Fuzzy Logic to Analyse Marketing Data", International Journal of Market Research, 47, 2, 205-228.
    Abstract:Traditional variable-centred analyses of marketing data are not well suited to the discovery of logical relationships between combinations of factors. This paper suggests that we may need to rethink what we mean by a 'case' and to view cases as configurations of characteristics rather than units of analysis. The processes of using combinatorial logic and fuzzy logic are explained. A new piece of software is introduced and applied to a dataset so that traditional analysis and fuzzy-set qualitative comparative analysis results can be compared.

  51. KLIR, George J., CLAIR, Ute St., and YUAN, Bo (1997), Fuzzy Sets Theory. Foundations and Applications, Englewood Cliffs, NJ, Prentice Hall PTR.

  52. KOGUT, Bruce (2010), "Qualitative Comparative Analysis of Social Science Data", in MORGAN, Glenn, CAMPBELL, John, CROUCH, Colin, PEDERSEN, Ove Kai, and WHITLEY, Richard (eds), The Oxford Handbook of Comparative Institutional Analysis , Oxford, Oxford University Press, pp. 139-179.
    Abstract:Introduction Classical Model of the Nineteenth Century Charles Ragin and Multiple Conjunctural Analysis: Configurations Counterfactuals Counterfactuals, Paul Tetlock, and Lars-Erik Cederman Counterfactuals and Gary King Comparison to Statistical Approaches: Example of Varieties of Capitalism Criticism of Qualitative Comparative Analysis Fuzzy Set Logic Multi-level Analysis Statistical Approaches: Multi-level Analysis and the Ecological Fallacy Looking Forward: Mechanisms and Simulation.

  53. KOSKO, Bart (1993), Fuzzy Thinking: the New Science of Fuzzy Logic, New-York, Hyperion.

  54. KROOK, Mona Lena (09.08.2005/09.10.2005), "Temporality and Causal Configurations: Combining Sequences Analysis and Fuzzy Set/Qualitative Comparative Analysis", paper presented at : General Conference of the European Consortium for Political Research, Budapest Hungary,
    Abstract: time & sequence.

  55. KUEHN, David and ROHLFING, Ingo (2009), "Does It, Really? Measurement Eror and Omitted Variables in Multi-Method Research", Qualitative and Multi-Method Research, 7, 2, 18-21.
    Abstract: A recurring tenet in much of the recent discussion on combining case studies and regression analyses and, to a lesser degree, case studies and QCA, highlights the purported ability of Multi-Method Research (MMR) to overcome the classic problems attached to each of the individual methods. The large- N part is employed to uncover cross-case regularities and causal effects, while in-depth case studies are undertaken to identify causal mechanisms in a subset of cases. In this, one purpose of case studies is to cross-validate the insights of the large-N analysis by identifying possible measurement error and exposing potentially omitted variables. Thereby, it is assumed, case studies are able to make the large-N analysis more robust. In this essay, we critically revisit these arguments from a methodological perspective. We argue that the ability of case studies to effectively enhance the inferential quality of the large-N method is significantly limited due to the very problems that they are supposed to solve: measurement error and omitted variables. While there is some discussion of these two issues on the cross-case level (King, Keohane, and Verba 1994; Lieberson 1991), there is only limited and largely implicit reflection on their relevance for the within-case level. This is unfortunate, as measurement errors and omitted variables on the within-case level are no less damaging for the inferential power of case studies as they are for large-N analyses. Measurement error and omitted variables are particularly likely to occur in process tracing because of problems in the use of sources for data collection and the generation of inferences on the basis of this data. We, therefore, maintain that the ability of the case study to serve as a double check on the quantitative part of MMR designs is overestimated. To be sure, many of the issues we highlight in this paper have been thrown up in the methods debate before. However, we think there is an insufficient transfer of the arguments made in the realm of the case study literature to the work on MMR, which is what we aim to achieve in the following.

  56. KVIST, John (2007), "Fuzzy Set Ideal Type Analysis", Journal of Business Research, 60, 474-481.

  57. KVIST, Jon (2003), "Conceptualisation, Configuration, and Categorisation. Diversity, Ideal Types and Fuzzy Sets in Comparative Welfare State Research", COMPASSS Working Paper 2003-15, 15,
    Abstract: This paper advances a new method for studying ideal types, fuzzy-set theory, which is a framework that allows a precise operationalisation of theoretical concepts, the configuration of concepts into analytical constructs, and the categorisation of cases. In a Weberian sense ideal types are analytical constructs used as yardsticks to measure the similarity and difference between concrete phenomena. Ideal type analysis involves differentiation of categories and degrees of membership of such categories. In social science jargon, this means analysis involving the evaluation of qualitative and quantitative differences or, in brief, of diversity. Fuzzy set theory provides a calculus of compatibility. It can measure and compute theoretical concepts and analytical constructs in a manner that is true to their formulation and meaning. This paper sets out elements and principles of fuzzy set theory that are useful for ideal type analysis and presents two illustrative examples of how it can be used in comparative studies. The examples concern changing Nordic welfare policies in the 1990s, unemployment and child family policies, and relate to their conformity to predefined ideal typical models.

  58. KVIST, Jon (2004), "Conceptualisation, Configuration, and Categorisation. Diversity, Ideal Types and Fuzzy Sets in Comparative Welfare State Research", paper presented at : ESF Exploratory Workshop on "Innovative Comparative Methods for Policy Analysis", Erfurt,

  59. LEE, Seungyoon Sophia (2008), "A Critique of the Fuzzy-Set Methods in Comparative Social Policy. A Critical Introduction and Review of the Applications of Fuzzy-Set Methods.", COMPASSS Working Paper WP 2008-53, 2008-53,
    Abstract: This article critiques the Fuzzy-Set Qualitative Analysis (fs/QCA) methodology by examining its applicability in three studies in the field of comparative social policy. In each of these three test cases, I focus on the validity of Fuzzy-Set’s claimed function – its ability to combine theoretic discourse and evidence analysis. All three studies investigate welfare state reform in the late twentieth century and apply fs/QCA: (1) “Welfare Reform in the Nordic Countries in the 1990s: Using Fuzzy-Set Theory to Assess Conformity to the Ideal Types,” (2) States of Welfare or States of Workfare? Welfare State Restructuring in the 16 Capitalist Democracies, 1985-2002,” and (3) “The Diversity and Causality of Welfare State Reforms Explored with Fuzzy-Sets.” This article begins by discussing the ontology and epistemology of comparative social policy. The Fuzzy-Set logic and set theoretic nature of social science theory is then discussed to align ontology with Fuzzy-Set methodology. Next, a more detailed introduction of Fuzzy-Set methods (fs/QCA) is followed. This study suggests that fs/QCA is a unique and useful method for comparative social policy. It advances quantitative comparative analysis by in interpreting attributes as a configuration. By applying Fuzzy-Set logic and the principle of calibration, it advances qualitative analysis by permitting theoretically-informed concepts to the quantified.

  60. LIEBERSON, Stanley (1985), Making It Count : the Improvement of Social Research and Theory, Berkeley, University of California Press.

  61. LONGEST, K. C. and VAISEY, S. (2008), "Fuzzy: a Program for Performing Qualitative Comparative Analyses (Qca) in Stata", Stata Journal, 8, 1, 79-104.
    Abstract: Qualitative comparative analysis (QCA) is an increasingly popular analytic strategy, with applications to numerous empirical fields. This article briefly discusses the substantive motivation and technical details of QCA, as well as fuzzy-set QCA, followed by an in-depth discussion of how the new program fuzzy performs these techniques in Stata. An empirical example is presented that demonstrates the full suite of tools contained within fuzzy, including creating configurations, performing a series of statistical tests of the configurations, and reducing the identified configurations.

  62. MAGGETTI, Martino (2007), "De Facto Independence After Delegation: A Fuzzy-Set Analysis", Regulation & Governance, 1, 271-294.
    Abstract: The phenomenon of delegating public authority from elected politicians (or ministries headed by elected politicians) to formally independent regulatory agencies (RAs) is becoming increasingly widespread. This paper examines the relation between formal independence, as prescribed in the constitutions of agencies, and de facto independence. Toward this end, it conceptualizes and assesses de facto independence of RAs, and discusses organizational, institutional, and political explanations for divergence from formal independence. The complex relations between de facto and formal independence are examined with a cross-national, cross-sectoral comparison of 16 Western European RAs using fuzzy-set analysis. The results show that formal independence is neither a necessary nor a sufficient condition for explaining variations in the de facto independence of agencies. Other factors, such as the lifecycle of agencies, veto players, and European networks of agencies, have a decisive impact.

  63. MAHONEY, James (2004), "Introduction: A Note on Terminology", Qualitative Methods: Newsletter of the American Political Science Association Organized Section on Qualitiative Methods, 2, 2, 2.

  64. MAHONEY, James (2004), "Reflections on Fuzzy-Set/QCA", Qualitative Methods: Newsletter of the American Political Science Association Organized Section on Qualitiative Methods, 2, 2, 17-21.

  65. MAHONEY, James (2010), Colonialism and Postcolonial Development. Spanish America in Comparative Perspective, New York, Cambridge University Press.

  66. MAHONEY, James and GOERTZ, Gary (2004), "The Possibility Principle: Choosing Negative Cases in Comparative Research", American Political Science Review, 98, 4, 653-669.

  67. ---------- (2004), "The Possibility Principle: Choosing Negative Cases in Comparative Research", COMPASSS Working Paper, 18, 27p.
    Abstract: A central challenge in qualitative research involves selecting the “negative” cases (e.g., nonrevolutions, nonwars) to be included in analyses that seek to explain positive outcomes of interest (e.g., revolutions, wars). Although it is widely recognized that the selection of negative cases is consequential for theory testing, methodologists have yet to formulate specific rules to inform this selection process. In this paper, we propose a principle – the Possibility Principle – that provides explicit, rigorous, and theoretically-informed guidelines for choosing a set of negative cases. The Possibility Principle advises researchers to select only negative cases where the outcome of interest is possible. Our discussion elaborates this principle and its implications for current debates about case selection and strategies of theory testing. Major points are illustrated with substantive examples from studies of revolution, economic growth, welfare states, and war.

  68. MANNEWITZ, Tom (2011), "Two-Level Theories in QCA: a Discussion of Schneider and Wagemann's Two-Step Approach", COMPASSS Working Paper 2011-64, 2011-64,
    Abstract: Comparative methods based on set theoretic relationships, such as ‘fuzzy set Qualitative Comparative Analysis’ (fs/QCA) represent an useful tool for dealing with complex causal hypotheses in terms of necessary and sufficient conditions under the constraint of a mediumsized number of cases. However, real world research situations might make the application of fs/QCA difficult in two respects, namely, with regard to the complexity of the results and the phenomenon of limited diversity. We suggest a two-step approach as one possibility to mitigate these problems. After introducing the difference between remote and proximate factors, the application of a two-step fs/QCA approach is demonstrated analysing the causes of the consolidation of democracy. We find that different paths lead to consolidation but all of them are characterised by a fit of the institutional mix chosen to the societal context in terms of power dispersion. Hence, we demonstrate that the application of fs/QCA in a twostep manner helps to formulate and test equifinal and conjunctural hypotheses in medium-size N comparative analyses and, thus, to contribute to an enhanced understanding of social phenomena.

  69. MOURY, Catherine (2004), "Les Ensembles Flous pour y voir plus clair: décoder les caractéristiques des accords de coalition en Europe Occidentale", Revue Internationale de Politique Comparée, 11, 1, 101-115.

  70. NI, Ning and YANG, Yu-Hong (2009), "How to Apply Fuzzy-Set Qualitative Comparative Analysis to Competency Modeling", Industrial Engineering and Management, 109-13.
    Abstract: Competency is a kind of holistic attribute and beneath the level of perceivable trait and behavior. Traditional modeling method tends to incur mechanical fit between certain behavior and certain competency,or between certain competency and certain mission. This may be caused by limitation of traditional statistical method used in data analyze period. Fortunately, set-theoretic approach can get rid of those limitations. In addition, dislike traditional statistical method, set-theoretic approach needs not large sampling in those complex research designs. This paper introduces the process how to use set-theoretic approach in competency modeling.

  71. NOMURA, Hisako (3-5th June 2008), "Transforming Variable Using SPSS/TOSMANA for QCA Analysis", paper presented at : Expert Roundtable on the Study of Strategies of Social Change Using the Method of Qualitative Comparatvie Analysis (QCA), Manchester,

  72. Olsen, Wendy, "Intermediate Level Qualitative Comparative Analysis Including Fuzzy Sets." (2004): 31 pp. 2004.

  73. OLSEN, Wendy (2009), "Non-Nested and Nested Cases in a Socio-Economic Village Study", in DAVID, Byrne and RAGIN, Charles (eds), The SAGE Handbook of Case-Based Methods, England, Sage, pp. 494-510.

  74. PENNINGS, Paul (2003), "Beyond Dichotomous Explanations: Explaining Constitutional Control of the Executive With Fuzzy-Sets", European Journal of Political Research, 42, 4, 541-568.
    Abstract: What are the main variations in the constitutional control of the executive in 45 parliamentary democracies and how can these differences be accounted for? Four competing hypotheses, based on dichotomies, explain the degree of this control by means of contrasting institutional settings: consensus democracy versus majoritarian democracy, presidentialism versus parliamentarism, thick versus thin constitutionalism and established versus new democracies. These hypotheses are tested with the help of fuzzy-sets that allow for varying degrees of membership which go beyond the presence/absence suggested by these dichotomies. The necessary and sufficient conditions for constitutional control are specified with the help of this new methodology. The fuzzy-set analysis shows that the degree of constitutional control can be explained solely by a specific combination of institutional conditions stemming from the four dichotomies and not by one single dimension. This constellation remains hidden for the traditional correlational techniques like regression. Hence, the fuzzy-set logic presents a promising new tool for comparativists that can be used to reveal causalities. .

  75. PENNINGS, Paul (2003), "The Methodology of the Fuzzy-Set Logic", in PICKEL, Susanne, PICKEL, Gert, LAUTH, Hans-Joachim, and JAHN, Detlef (eds), Vergleichende Politikwissenschaftliche Methoden. Neue Entwicklungen und Diskussionen, Wiesbaden, Westdeutscher Verlag, pp. 87-103.

  76. ---------- (2008), "Fuzzy-Sets and QCA - The Methodology of the Fuzzy-Set Logic and Its Application", in PICKELS, Susanne, PICKEL, Gert, LAUTH, Hans-Joachim, and JAHN, Detlef (eds), Methoden der vergleichenden Politik- und Sozialwissenschaft. Neue Entwicklungen und Anwendungen, Wiesbaden, VS-Verlag, pp. ²347-364.

  77. PHILLIPS, Dianne (2003), "Review Article: Research Training by the Package", Sociology, 37, 1, 165-172.

  78. PICKEL, Susanne, PICKEL, Gert, LAUTH, Hans-Joachim, and JAHN, Detlef (eds) (2003), Vergleichende Politikwissenschaftliche Methoden. Neue Entwicklungen und Diskussionen, Wiesbaden, Westdeutscher Verlag.

  79. QUARANTA, Mario (2010), "Concept Structures and Fuzzy Set Theory: a Proposal for Concept Formation and Operationalization", COMPASSS Working Paper 2011-62, 2011-62,
    Abstract: Concept formation strategies can be divided in positivist or interpretivist approaches. The first relies on classification and taxonomy strategies as tools for concept formation, while the second draws on hermeneutics and uses the ideal type for the definition of concepts. I argue that both have limits concerning concept formation. The positivist approach has strong naturalist assumptions, which can be inadequate to take into account the contingency of the empirical world. By contrast, the interpretivist one is very focused on the historical specificity of concepts, which may lead to their inapplicability. A solution to these problems comes from fuzzy set theory. This holds a potential for concept formation because it has as its main strengths the possibility of configurational thinking and the use of the truth table. Concepts can be built including all the possible attributes into a table and this can have several advantages. Fuzzy set theory also contributes to the creation of partial concepts, representing configurations or sub-types. In this paper, I develop this strategy, illustrating, first, the weaknesses and the strengths of the classical approaches. Then, I discuss the ontology and logic behind fuzzy set theory and demonstrate that it can be a very useful approach to concept formation. In the end, I test applying this strategy to the concept of political participation.

  80. RAGIN, Chalres (2009), "Reflections on Casing and Case Oriented Research", in BYRNE, David and RAGIN, Charles (eds), The SAGE Handbook of Case-Based Methods , England, Sage, pp. 522-543.

  81. RAGIN, Charles (2003), "Recent Advances in Fuzzy-Set Methods and Their Application to Policy Questions", COMPASSS Working Paper, 9, 33p. (http://www.compasss.org/Ragin2003.PDF)
    Abstract: Fuzzy sets have many potential applications in the social sciences. The ideas and suggestions presented in Fuzzy-Set Social Science scratch only the bare surface of their potential uses, for there are many ways to integrate fuzzy sets (and set-theoretic thinking more generally) into social research. In this paper, I sketch several recent advances in fuzzy-set methods, illustrating them with examples drawn from policy research. While these new fuzzy-set methods build on arguments presented in Fuzzy-Set Social Science, they also forge a strong link to some of the crisp-set principles presented in The Comparative Method, especially those concerning the issue of limited diversity. Thus, the techniques presented in this paper are generally relevant to both crisp-set and fuzzy-set analysis. The first advance I present is the elaboration and refinement of the concepts of "consistency" and "coverage" in set-theoretic analysis. Specifically, I show how to assess the consistency and coverage of combinations of causal conditions. Consistency concerns the degree to which a combination of causal conditions is consistent with an argument of sufficiency; coverage concerns the relative importance of combinations of sufficient conditions in the effort to explain or "cover" instances of the outcome. In this discussion I emphasize the fuzzy-set analysis of sufficient combinations of causal conditions, but the two principles apply just as well to the fuzzy-set analysis of necessary conditions and to the analysis of necessity and sufficiency as set-theoretic relations using crisp sets. The second advance I discuss is a new algorithm for the incorporation of "simplifying assumptions" into the results of applications of QCA and fs/QCA. This new algorithm allows the direct incorporation of theoretical and substantive knowledge into the evaluation of simplifying assumptions in situations of "limited diversity" (which is the rule in the study of naturally occurring social phenomena). I illustrate this algorithm with crisp sets, and then extend it to fuzzy sets. Along the way, I also introduce a new algorithm for the fuzzy-set analysis of social data. The new algorithm is more amenable to the analysis of limited diversity than the one presented in Fuzzy-Set Social Science.

  82. ---------- (9.16.2003/9.17.2003), "Recent Advances in Fuzzy-Set Methods and Their Application to Policy Questions", paper presented at : COMPASSS Launching Conference, Louvain-la-Neuve and Leuven, Belgium,

  83. ---------- (2004), "From Fuzzy Sets to Crisp Truth Tables", COMPASSS Working Paper - Re-Worked Version of the WP2004-26, 28, 34p.
    Abstract: 1 One limitation of the truth table approach is that it works best when causal conditions are simple presence/absence dichotomies (i.e., Boolean or "crisp" sets). Many of the causal conditions that interest social scientists, however, vary by level or degree. For example, while it is clear that some countries are democracies and some are not, there are many in-between cases. These countries are not fully in the set of democracies, nor are they fully excluded from this set. Fortunately, there is a well-developed mathematical system for addressing partial membership in sets, fuzzy-set theory. Section 2 of this paper provides a brief introduction to the fuzzyset approach, building on Ragin (2000). Fuzzy sets are especially powerful because they allow researchers to calibrate partial membership in sets using values in the interval between 0 (nonmembership) and 1 (full membership) without abandoning core set-theoretic principles, for example, the subset relation. Ragin (2000) demonstrates that the subset relation is central to the analysis of multiple conjunctural causation, where several different combinations of conditions are sufficient for the same outcome. While fuzzy sets solve the problem of trying to force-fit cases into one of two categories (membership versus nonmembership in a set), they are not well suited for conventional truth table analysis. With fuzzy sets, there is no simple way to sort cases according to the combinations of causal conditions they display because each case's array of membership scores may be unique. Ragin (2000) circumvents this limitation by developing an algorithm for analyzing configurations of fuzzy-set memberships that bypasses truth tables altogether. While this algorithm remains true to fuzzy-set theory through its use of the containment (or inclusion) rule, it forfeits many of the analytic strengths and virtues that follow from analyzing evidence in terms of truth tables. For example, truth tables are very useful for investigating "limited diversity" and the consequences of different "simplifying assumptions" that follow from the use of different subsets of "remainders" to reduce complexity (see Ragin 1987; Ragin and Sonnett 2004). Analyses of this type are difficult without using a truth table as the starting point. Ragin and Sonnett (2004), for example, show how to use QCA to aid counterfactual analysis and link the analysis of counterfactual conditions to core practices in case-oriented research. Truth tables are central to the analysis of counterfactuals, and the techniques described in Ragin and Sonnett (2004) cannot be implemented without the aid of truth tables. Section 3 of this paper builds a bridge between fuzzy sets and truth tables, demonstrating that it is possible to construct a conventional Boolean truth table from fuzzy-set data. It is important to point out that this new technique takes full advantage of the gradations in set membership central to the constitution of fuzzy sets and is not predicated on a dichotomization of fuzzy membership scores. To illustrate these procedures I use data collected on class voting in the advanced industrial societies, compiled by Paul Nieuwbeerta (see, e.g., Nieuwbeerta and de Graaf 1999; Nieuwbeerta and Ultee 1999; Nieuwbeerta, de Graaf and Ultee 2000). It is important to point out that the approach sketched in this paper offers a new way to conduct fuzzy-set analysis of social data. This new analytic strategy is superior in several respects to the one sketched in Fuzzy-Set Social Science (Ragin, 2000). While both approaches have strengths and weaknesses, the one presented here uses the truth table as the key analytic device. A further advantage of the fuzzy-set truthtable approach presented in this paper is that it is more transparent. Thus, the researcher has more direct control over the process of data analysis. This type of control is central to the practice of case-oriented research.

  84. RAGIN, Charles (09.06.2007/09.08.2007), "Using Fuzzy Sets and Qualitative Comparative Methods to Analyse Longitudinal Data", paper presented at : 4th ECPR General Conference, Panel on "Comparative Research Design and Configurational Methods", Pisa,

  85. RAGIN, Charles (2009), " Book Reviews", Swiss Political Science Review, 15, 2, 395-426.

  86. RAGIN, Charles C. (1998), "Comparative Methodology, Fuzzy Sets and the Study of Sufficient Causes", APSA-CP. Newsletter of the APSA Organized Section in Comparative Politics, 9, 1, 18-22. (Online at : http://www.nd.edu/~apsacp/pdf/APSA-CP_Winter_1998.pdf)
    Abstract: Preview of some of the arguments of the 2000 book on fuzzy sets.

  87. RAGIN, Charles C. (2000), Fuzzy-Set Social Science, Chicago, Chicago University Press.

  88. RAGIN, Charles C. (2002), Course Content. Analyzing Qualitative Data on "Multiple Instances" (unpublished manuscript).

  89. ---------- (2004), "Innovative Causal Analysis and Policy Research", paper presented at : European Science Foundation Exploratory Workshop on “Innovative Comparative Methods for Policy Analysis. An Interdisciplinary European Endeavour for Methodological Advances and Improved Policy Analysis/Evaluation.”, Erfurt, Germany,

  90. RAGIN, Charles C. (2006), "The Limitations of Net-Effects Thinking", in RIHOUX, Benoît and GRIMM, Heike (eds), Innovative Comparative Methods for Policy Analysis, New-York, Springer, pp. 13-41.

  91. ---------- (2006), "Set Relations in Social Research: Evaluating Their Consistency and Coverage", Political Analysis, 14, 3, 291-310.

  92. ---------- (2007), "Calibration Versus Measurement ", in COLLIER, David, BRADY, Henry, and BOX-STEFFENSMEIER, Janet (eds), Methodology Volume of Oxford Handbooks of Political Science, New-York, Oxford University Press,

  93. ---------- (2007), "Fuzzy Sets: Calibration Versus Measurement", COMPASSS Working Paper, 44, 37p.
    Abstract: This essay explores the connections between measurement and calibration in the social sciences and addresses its long-standing neglect. My starting point is the contrast between conventional approaches to measurement in quantitative and qualitative social research. After sketching common measurement practices in both types of research, I argue that a useful way for social scientists to incorporate measurement calibration into their research is through the use of fuzzy sets. In order to use fuzzy sets effectively, researchers must assess the degree of membership of cases in well defined sets (e.g., degree of membership in the set of "developed countries"). This requirement forces researchers to attend to the issue of calibration and provides additional motivation for them to explore the conceptual underpinnings of their measures. Fuzzy sets resonate with the measurement concerns of qualitative researchers, where the goal often is to distinguish between relevant and irrelevant variation--that is, to interpret it--and with the measurement concerns of quantitative researchers, where the goal is the precise placement of cases relative to each other. The second half of this essay sketches a technique for calibrating conventional interval- and ratio-scale variables according to external standards. In the examples provided, the external standard used is a qualitative assessment of the degree to which cases with given scores on a conventional interval-scale measure are members of a target set. A simple estimation technique rescales the interval-scale measure so that it conforms to these qualitative assessments. The end product of this procedure is the calibration of the degree of membership of cases in sets, which in turn is suitable for fuzzy-set and other types of analysis. The examples illustrate the responsiveness of this calibration technique to the researcher's qualitative assessments of cases. While calibration in the social sciences is unlikely ever to match the sophistication of calibration in the physical sciences, the technique of qualitative calibration presented here is an important first step.

  94. ---------- (2008), Redesigning Social Inquiry: Fuzzy Sets and Beyond, Chicago, Chicago University Press.

  95. ---------- (2009), "Qualitative Comparative Analysis Using Fuzzy Sets (FsQCA)", in RIHOUX, Benoît and RAGIN, Charles C. (eds), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques , Thousand Oaks and London, Sage,

  96. RAGIN, Charles C. (forthcoming), "Fuzzy Sets: Calibration Versus Measurement", in COLLIER, David, BRADY, Henry, and BOX-STEFFENSMEIER, Janet (eds), Methodology Volume of Oxford Handbooks of Political Science

  97. RAGIN, Charles C. and PENNINGS, Paul (May 2005), "Fuzzy Sets and Social Research", Sociological Methods and Research, 33, 4, 423-430.

  98. RIHOUX, Benoît (09.20.2009), "Latest Innovations in Configurational Comparative Methods and the Challenges Ahead", paper presented at : The Second Japan-UK Roundtable on the Frontiers of the Qualitative Comparative Method, Sapporo,

  99. RIHOUX, Benoît and ENGELI, Isabelle (2012, forthcoming), "Intermediate-N Comparison: Configurational Comparative Methods", in ENGELI, Isabelle and ROTHMAYR, Christine (eds), Comparative Policy Studies: Conceptual and Methodological ChallengesPalgrave, Louvain-la-Neuve and Erfurt, 2005.

  100. RIHOUX, Benoît (2004), "Six applications d'Analyse Quali-Quantitative Comparée (AQQC) et des Ensembles Flous (EF): mode d'emploi et originalités [Six applications of Qualitative Comparative Analysis (QCA) and Fuzzy Sets: instructions for use and original features]", Revue Internationale de Politique Comparée, 11, 1, 11-16.

  101. ---------- (2006), "Qualitative Comparative Analysis (QCA) and Related Systematic Comparative Methods: Recent Advances and Remaining Challenges for Social Science Research", International Sociology, 21, 5, 679-706.

  102. ---------- (2008), "Case-Orientated Configurational Research: Qualitative Comparative Analysis (QCA), Fuzzy Sets, and Related Techniques", in BOX-STEFFENSMEIER, Janet, BRADY, Henry, and COLLIER, David (eds), The Oxford Handbook of Political Methodology, Oxford, Oxford University Press, pp. 722-736.

  103. ---------- (2008), "Qualitative Comparative Analysis (QCA) and Related Techniques: Recent Advances and Challenges", in PICKEL, Susanne, PICKEL, Gert, LAUTH, Hans-Joachim, and JAHN, Detlef (eds), Methoden der vergleichenden Politik- und Sozialwissenschaftt. Neuere Entwicklungen und Anwendungen, Wiesbaden, VS-Verlag , pp. 365-386.

  104. ---------- (2011, forthcoming), "Configurational Comparative Methods", in BECK, Nathaliel (ed.), IPSA Encyclopedia of Political Science. Methodology Volume, Thousand Oaks, London and New Delhi, Sage,

  105. RIHOUX, Benoît, BOL, Damien, and REZSÖHAZY, Ilona (2012 forthcoming), "Qualitative Comparative Analysis (QCA) in Public Policy Analysis: an Extensive Review", German Policy Studies,

  106. RIHOUX, Benoît and RAGIN, Charles C. (9.2.2004/9.5.2004), "Qualitative Comparative Analysis (QCA): State of the Art and Prospects", paper presented at : APSA 2004 Annual Meeting, Panel 47-9, Chicago,

  107. SCHNEIDER, Carsten (2006), "Qualitative Comparative Analysis Und Fuzzy Sets", in BEHNKE, Joachim, GSCHWEND, Thomas, SCHINDLER, Delia, and KNAPP, Kai-Uwe, Methoden Der Politikwissenschaft. Neuere Qualitative Und Quantitative Analyseverfahren , Baden Baden, Nomos Verlag, pp. 273-286.

  108. SCHNEIDER, Carsten Q. (07.15-16.2006), "It Might Look Like a Regression Equation... But It's Not! An Intuitive Approach to the Presentation of QCA and FS/QCA Results", paper presented at : International Conference on Comparative Social Sciences , Tokyo, Japan,

  109. SCHNEIDER, Carsten Q. and GROFMAN, Bernard (2006), "It Might Look Like a Regression Equation... but It Is Not! An Intuitive Approach to the Presentation of QCA and FSQCA Results", COMPASSS Working Paper , 39, 61p.
    Abstract: Scholars who have presented their QCA and fs/QCA results in conference papers or journal articles will most likely have encountered the problem that an audience not trained in these approaches tends to read the notations and graphs displaying the results as if they stemmed from standard statistical techniques such as linear regression or factor analysis. This leads to gross misunderstandings, since the underlying mathematical models and the epistemology are different, and because the notations and graphs used in QCA and fs/QCA carry a different meaning than similar looking ones in standard statistical approaches. Thus readers may think they know what’s going in QCA analyses when they really don’t. The main aim of this paper is to offer seven ways, some new to this paper, of presenting results in QCA and fs/QCA that are designed to make the interpretability of results from these methods clearer and more intuitive: (1) truth tables; (2) solution formulas; (3) parameters of fit; (4) Venn diagrams; (5) dendograms; (6) x-y plots; and (7) membership scores for solution terms – the latter two only appropriate for fuzzy set QCA. We show that each form tends to be confused with one or more presentational formscommonly used in standard statistical techniques, its “false friend(s),” and thus misinterpreted; and so we try to clarify the implications of each of these presentational tools by pointing out what they do not mean. Generally speaking, the presentation of results generated with any kind of method applied in comparative social research has multiple purposes, not all of which can always be achieved simultaneously in one presentational form. In grosso modo, the presentation of results aims at: (a) displaying relations between variables; (b) highlighting descriptive or causal accounts for specific (groups of) cases; (c) expressing the fit of the result obtained with the data at hand. Trying to accomplish all three of these purposes is particularly important for QCA and fs/QCA because they have been explicitly introduced as methods for bridging the gap between qualitative (case-oriented) and quantitative (variableoriented) approaches of social scientific research. While the individual presentational forms serve one or more (but never all) of the three above-mentioned purposes, using a combination of them in a fashion that covers all three bases allows us to display the full potential and logic of QCA and fs/QCA methods.

  110. ---------- (09.06.2007/09.08.2007), "Graphical Representations of Fuzzy Set Results: How Not to Get Your Audience Confused", paper presented at : 4th ECPR General Conference, Panel on "Comparative Research Design and Configurational Methods", Pisa,

  111. SCHNEIDER, Carsten Q. and WAGEMANN, Claudius (7.4.2002/7.7.2002), "Limited Diversity Limited Applicability? The Role of Theory in QCA-Based Studies of Democratisation ", paper presented at : "Methods of Comparative Political Science. Procedure and Examples of International and Inter-Cultural Comparative Studies" of the DVPW-Working Group "Intercultural Comparison of Democracy", University Greifswald, Germany,

  112. ---------- (9.2.2004/9.5.2004), "The Fuzzy-Set/QCA Two-Step Approach to Middle-Range Theories", paper presented at : APSA 2004 Annual Meeting, Chicago,

  113. ---------- (2006), "Reducing Complexity in Qualitative Comparative Analysis (QCA): Remote and Proximate Factors and the Consolidation of Democracy", COMPASSS Working Paper - Re-Worked Version of the WP2002-1, 35, 61p.
    Abstract: Comparative methods based on set theoretic relationships, such as ‘fuzzy set Qualitative Comparative Analysis’ (fs/QCA) represent an useful tool for dealing with complex causal hypotheses in terms of necessary and sufficient conditions under the constraint of a mediumsized number of cases. However, real world research situations might make the application of fs/QCA difficult in two respects, namely, with regard to the complexity of the results and the phenomenon of limited diversity. We suggest a two-step approach as one possibility to mitigate these problems. After introducing the difference between remote and proximate factors, the application of a two-step fs/QCA approach is demonstrated analysing the causes of the consolidation of democracy. We find that different paths lead to consolidation but all of them are characterised by a fit of the institutional mix chosen to the societal context in terms of power dispersion. Hence, we demonstrate that the application of fs/QCA in a twostep manner helps to formulate and test equifinal and conjunctural hypotheses in medium-size N comparative analyses and, thus, to contribute to an enhanced understanding of social phenomena.

  114. SCHNEIDER, Carsten Q. and WAGEMANN, Claudius (2007), Qualitative Comparative Analysis (QCA) und Fuzzy Sets. Ein Lehrbuch für Anwender und jene, die es werden wollen, Opladen & Farmington Hills, Verlag Barbara Budrich.

  115. SCHNEIDER, Carsten Q. and WAGEMANN, Claudius (2008), "Standards guter Praxis in Qualitative Analysis (QCA) und Fuzzy-Sets", in PICKEL, Susanne, PICKEL, Gert, LAUTH, Hans-Joachim, and JAHN, Detlef (eds), Neue vergleichende sozialwissenschaftliche Methoden, Wiesbaden, VS-Verlag, pp. 387-412/.

  116. ---------- (forthcoming), Qualitative Comparative Analysis (QCA) and Fuzzy Sets. A User's Guide,

  117. SCHRODT, Philip A. (2002), "Book Review: Fuzzy-Set Social Science. By Charles Ragin.", American Political Science Review, 96, 2, 452-453.

  118. SIVESIND, Karl Henrik and SELLE, Per (07.11.2004/07.14.2004), "Is There a Social Democratic Civil Society Regime in the Welfare Field?", paper presented at : Paper Presented at the International Society for Third-Sector Research (ISTR) Sixth International Conference, Toronto,
    Abstract: It is frequently assumed that voluntary and nonprofit organizations play a limited role in welfare service provision in the Nordic, social democratic countries. The public sector has the main responsibility for meeting the population’s welfare needs (Janoski 1998; Salamon & Anheier 1998). This paper confronts this assumption with results from a comparative analysis of highly industrialized countries with extensive welfare arrangements. We focus on civil society sector employment in relation to total employment in the welfare field, including education and research, health, and social services. Explanatory factors are public welfare spending, share of income from donations, and religious homogeneity. Qualitative Comparative Analysis (QCA) (Ragin 2000) is applied to sort countries in types. The results show that the consequences of public sector welfare spending on civil society welfare employment vary depending on other social conditions. In liberal countries, low public sector welfare spending results in a small civil society share of employment. The preconditions are religious heterogeneity and large shares of civil society income from donations. In other Western European countries, the size of public sector welfare spending is inversely proportional with the size of the civil society share of employment, depending on religious heterogeneity. The Nordic countries have the smallest share of civil society welfare services, highest religious homogeneity, and largest public welfare costs. They do not represent a separate constellation of factors, but are closely followed by presumably corporatist countries like France and Austria. When data from Denmark are available and taken into account together with recent developments, the distinctiveness of the Nordic countries will probably be further reduced.

  119. SIVESIND, Karl Henrik and SELLE, Per (2009), "Does Public Spending “Crowd Out” Nonprofit Welfare?", in ENJOLRAS, Bernard and SIVESIND, Karl Henrik (eds), Civil Society in Comparative PerspectiveEmerald Group Publishing Limited, pp. 105-134.
    Abstract: Social origins theory proposes that countries cluster around different models according to how public welfare spending affects nonprofit sector scale (Anheier & Salamon, 2006; Salamon & Anheier, 1998). This article confronts these assumptions about a liberal, corporatist, and social democratic model with results from a comparative analysis of highly industrialized countries with extensive welfare arrangements. We focus on nonprofit sector employment in relation to total employment in the welfare field, including education and research, health, and social services. Explanatory factors are public welfare spending, share of income from donations, and religious homogeneity. Qualitative Comparative Analysis (QCA) (Ragin, 2000) is applied to sort countries in types. The results show that the consequences of public sector welfare spending on nonprofit welfare employment vary depending on other social conditions. In liberal countries, low public sector welfare spending results in a small nonprofit share of employment. The preconditions are low religious homogeneity and large shares of nonprofit income from donations. In other Western European countries, the size of public sector welfare spending is inversely proportional with the size of the nonprofit share of employment, depending on religious homogeneity. The Nordic countries have the highest religious homogeneity, and largest public welfare costs, and accordingly, the smallest share of nonprofit welfare services. However, a similar “crowding out” pattern can be found in the presumably corporatist countries such as France, Austria, and also to some extent in Germany and Italy. In the other end of the line, we find the Netherlands, which is the clearest example of the presumed corporatist pattern in this sample. Religious homogeneity comes into play in both the liberal and the Western European causal constellation in accordance with Weisbrod's theory of government failure/market failure (Weisbrod, 1977), which indicates that this factor is more important for nonprofit welfare regimes than previously thought.

  120. SKAANING, Svend-Erik (09.06.2007/09.08.2007), "Assessing the Robustness of Crisp-Set and Fuzzy-Set QCA Results", paper presented at : 4th ECPR General Conference, Panel on "Comparative Research Design and Configurational Methods", Pisa,

  121. SMITHSON, Michael (1986), Fuzzy Set Analysis for Behavioral and Social Science, New York, Springer Verlag.

  122. SMITHSON, Michael and VERKUILEN, Jay (02/2006), Fuzzy Set Theory. Applications in the Social Sciences, London, Sage Publications. (http://www.sagepub.com/book.aspx?pid=11575)
    Abstract: This book introduces fuzzy set theory to social science researchers. Fuzzy sets are categories with blurred boundaries. With classical sets, objects are either in the set or not, but objects can belong partially to more than one fuzzy set at a time. Many concepts in the social sciences have this characteristic, and fuzzy set theory provides methods for systematically dealing with them. A primary reason for not going beyond programmatic statements and rather unsophisticated uses of fuzzy set theory has been the lack of practical methods for combining fuzzy set concepts with statistical methods. This monograph takes that topic as its major focus, and provides explicit guides for researchers who would like to harness fuzzy set concepts while being able to make statistical inferences and test their models. Real examples and data-sets from several disciplines illustrate the techniques and applications, demonstrating how a combination of fuzzy sets and statistics enable researchers to analyze their data in new ways.

  123. STOKKE, Olav Schram (2003), "Boolean Analysis, Mechanisms, and the Study of Regime Effectiveness", COMPASSS Working Paper, 5, 35p.

  124. ---------- (May 2007), "Qualitative Comparative Analysis, Shaming, and International Regime Effectiveness", Journal of Business Research, 60, 5, 501-511.
    Abstract: The article presents and applies a set-theoretic comparative technique, qualitative comparative analysis (QCA), to a string of case studies on shaming as a strategy for improving the effectiveness of international regimes for resource management. This technique is particularly attractive when the number of cases available is greater than what the researcher can reliably handle by narrative comparison, yet too low to support statistical procedures. QCA can capture causal conjunctions, even in small-to-intermediate-N situations, primarily because it permits the introduction of simplifying assumptions in a way that maintains a clear connection to the underlying cases - thus allowing substantive evaluation of their plausibility. A more recent fuzzy-set version lifts two limitations of the crisp-set version of QCA examined here (i.e., that variables must be dichotomous, and that the analysis makes no allowance for measurement error and non-modeled causality).

  125. THIEM, Alrik (2010), "Set-Relational Fit and the Formulation of Transformational Rules in FsQCA", COMPASSS Working Paper 2010-61, 2010-61,
    Abstract: Interest in the application of fuzzy set Qualitative Comparative Analysis (fsQCA) has increased markedly among political scientists in recent years. Although fsQCA is often contrasted with regression analysis, questions of functional form have thus far been hardly addressed. However, functional form matters as much in the former tool kit of social enquiry as it does in the latter. This article demonstrates how coverage as a measure of set-relational fit can guide the formulation of transformational rules similar to the use of the coefficient of determination in regression-analytic tests of functional misspecification. Interaction effects between membership function and crossover anchor choice on coverage are analysed in the context of set-theoretic relations of sufficiency between condition and outcome. Depending on the relative location of the crossover anchor, changes in the transformational rules by which base variables are calibrated can increase or decrease coverage similar to the effect of changes in functional specification on the coefficient of determination. Most importantly, significant reductions in uncovered membership relative to total membership provide an explicit and transparent foundation on which calibration strategies can be based.

  126. THIEM, Alrik (04.19.2011//04.21.2011), "Set-Relational Fit and the Formulation of Transformational Rules in FsQCA", paper presented at : Paper Presented at the 61st PSA Annual Conference, London,
    Abstract: Interest in the application of fuzzy set Qualitative Comparative Analysis (fsQCA) has increased markedly among political scientists in recent years. Although fsQCA is often contrasted with regression-based methods, questions of functional form have thus far not been addressed. However, functional form matters as much in the former tool kit of social enquiry as it does in the latter. This article demonstrates how coverage as a measure of set-relational fit is influenced by the formulation of transformational rules similar to the coefficient of determination being influenced by functional specifications. Interaction effects between membership function and crossover anchor choice on coverage are analyzed in the context of set-theoretic relations of sufficiency between condition and outcome. Depending on the relative location of the crossover anchor, changes in the transformational rules by which metric base variables are calibrated influence coverage in either negative or positive directions. Most importantly for applied research, significant reductions in uncovered member- ship relative to total membership can be achieved because explicit foundations for calibration strategies are still lacking.

  127. VERKUILEN, Jay (Spring 2001), "Book Review: Charles Ragin, Fuzzy Set Social Science", paper presented at : APSA-CP: Newsletter of the APSA Organized Section in Comparative Politics, Washington D.C.,

  128. ---------- (8.30.2001/9.2.2001), "Measuring Fuzzy Set Membership Functions: a Dual Scaling Approach", paper presented at : Annual Meeting of the APSA, San Francisco,
    Abstract: Charles Ragin's (2000) recent book opened up a recent dialogue on fuzzy set methods in social science data analysis. Membership functions are measures of partial set membership and are normalized to be in the unit interval and have been used to characterize situations of non-probabilistic vagueness. One of the deficiencies of the fuzzy set literature has been a lack of a firm basis in measurement for membership functions, even though leading fuzzy set theorists have noted that any practical applications depend strongly on the quality of membership assessment. In this paper, I discuss the use of dual scaling, a method from nonlinear multivariate analysis that scales multiple categorical items for the assignment of fuzzy set membership functions. The paper also includes an example of the scaling applied to some data from Russett (1964) , that are very typical of the sort encountered in medium N cross-national research.

  129. --------- (10.2002), Methodological Problems in Comparative and Cross-National Analysis: Applications of Fuzzy Set Theory (PhD Dissertation),University of Illinois Urbana-Champaign (unpublished).
    Abstract: My dissertation makes a contribution to both quantitative and qualitative methodology by drawing upon fuzzy set theory. Quantitative methods, especially the traditional regression analysis, usually rely on largely hidden and unjustified assumptions such as the use of the mean as the reference point and the additivity of multiple variables. These assumptions are not necessarily innocuous. Furthermore, quantitative methods frequently rely overly much on proxy indicators that are frequently biased and do not capture the theoretical concepts adequately. On the other hand, qualitative methods have traditionally used complex, "thick" concepts that frequently impede clear communication, theories that are not sufficiently specified to be testable, and has been haunted by the "too many variables-too few cases" problem. In all of these areas, fuzzy set theory can be of assistance. Fuzzy set theory provides a useful mathematical language--an extension of formal logic--that is particularly suited to express testable claims that match the kind of theories generated by qualitative researchers and to test them in ways that do not violate the assumptions of these theories. In addition, fuzzy set theory provides a rigorous means to handle the vagueness inherent in complex concepts. I argue, thus, that even though fuzzy set theory has not been widely adopted, it offers a useful way to tackle key problems in both quantitative and qualitative methods and also to bridge the unproductive and ultimately unfounded quantitative-qualitative divide in political science and comparative politics. However, before it can be of broader appeal, a number of barriers to its use must be addressed. Seeking to realize the as yet unfulfilled promise of fuzzy set theory and to show in particular how it can be applied in the field of comparative politics, my dissertation addresses three basic issues. First, I show how to scale membership functions, the primary quantities necessary for fuzzy set analysis. This has been a particular deficiency of fuzzy set theory, which has impeded the more widespread use of fuzzy set theory in the social sciences. Thus, I help fill an important gap in the current discourse in fuzzy set theory itself. Second, I demonstrate how it can be used to aggregate multiple indicators so as to form indices for compound concepts. This is yet another critical aspect of the methodology of fuzzy set theory, given that social scientists and especially comparativists, routinely frame their research in terms of compound concepts such as democracy, development, the state, and so on. I show how these complex concepts can be developed in very clear, formal terms. Third, I turn to the problem of analyzing relationships among sets and show how fuzzy set theory offers a more suitable basis for the testing of theories than more established regression models. I concentrate primarily on relationships characterized by set inclusion, which can be used to formalize necessary conditions. The general focus is on noting which cases fit the predicted pattern and identifying deviant cases for further in-depth analysis. The techniques developed are illustrated throughout with examples taken from the literature, focusing primarily on research in political regime change, the relationship between inequality and political violence, and human development. They are particularly useful in a "medium-N" context, where the investigator can ensure validity of measurement and apply contextual knowledge to understand the results.

  130. VIEBROCK, Elke (9.9.2004/9.11.2004), "European Systems of Unemployment Insurance in Historical Comparison. The Potential of FS/QCA in Cross-Country Welfare State Research", paper presented at : ESPAnet 2004 Conference, Comparative Methodology Stream, Oxford,

  131. VIEBROCK, Elke and NORRIS, Paul (2005), "A Fuzzy-Set Based Analysis of Changing Levels of Social Expenditure in OECD Countries 1980-1998", paper presented at : ECPR General Conference, Budapest, Hungary,
    Abstract: The last twenty years have seen the development of an extensive literature which has used correlation and multiple regression analysis to attempt to identify those factors which best explain changing levels of social expenditure across industrialised countries. This literature has been criticised because the data on which it is based often fails to meet the assumptions of the statistical techniques employed, particularly with regards to the need for a large sample size. It has been suggested that fuzzy-set methods, as described by Ragin (2000), are one approach allowing causal relationships to be identified in samples with very limited numbers of cases. It is therefore possible that these methods could provide an opportunity for macro-level comparative studies of social expenditure that might overcome some of the problems associated with the use of traditional statistical methods. This paper presents a fuzzy-set based analysis of those factors associated with changing levels of social expenditure in OECD member nations between 1980 and 1998. This analysis is based on the data used by Francis G. Castles for his 2004 book “The Future of the Welfare State: Crisis Myths and Crisis Realities” and the paper concludes by comparing the results of the fuzzy-set analysis with those presented by Castles (whose work is based on multiple regression). This comparison highlights both the similarities and differences between the findings of the two methods and, as such, provides a useful practical example of the strengths and weaknesses of the two approaches.

  132. VIS, Barbara (2010), Politics of Risk-Taking: Welfare State Reform in Advanced Democracies , Amsterdam, Amsterdam University Press.

  133. WAGEMANN, Claudius (2007), "QCA e «Fuzzy Set Analysis». Che Cosa è e Che Cosa Non è", Rivista Italiana Di Scienza Politica, 37, 3, 385-410.
    Abstract: [In Italian] The article presents «Qualitative Comparative Analysis » (QCA), introduced in the 1980s and since then further developed by the American social scientist Charles C. Ragin. The QCA methodology is based on set-theoretical relationships, analyzing social science data with regard to sufficient and necessary conditions. Three aspects of causality are particularly emphasized in QCA, namely, equifinality, conjunctural causation, and assymmetric causation. The novelty of QCA consists in the fact that it allows the researcher to take complex causal structures into account. Fuzzy set QCA (fsQCA) enlarges the range of applicability even further. The article finishes with a discussion in how far QCA is really a «qualitative» method and proposes an agenda which issues regarding QCA should be settled in the next future, most importantly, the creation of a «code of good standard».

  134. WAGEMANN, Claudius and SCHNEIDER, Carsten (2010), "Qualitative Comparative Analysis (QCA) and Fuzzy-Sets: Agenda for a Research Approach and a Data Analysis Technique", Comparative Sociology, 9, 3, 376-396.
    Abstract: 'Qualitative Comparative Analysis' (QCA) is an increasingly applied methodological tool in comparative social sciences. It is well suited for the analysis of causally complex claims framed in terms of necessity and sufficiency. This article presents the epistemology of QCA and discusses its applicability to social science research questions. It also illustrates some of the features that have recently been added to this set of methodological tools. This article is best read in close conjunction with Schneider and Wagemann's 'Standards of Good QCA Practice,' the next paper in this journal issue.

  135. WAGEMANN, Claudius and SCHNEIDER, Carsten (2010), "Standards of Good Practice in Qualitative Comparative Analysis (QCA) and Fuzzy-Sets", Comparative Sociology, 9, 3, 397-418.
    Abstract: As a relatively new methodological tool, QCA is still a work in progress. Standards of good practice are needed in order to enhance the quality of its applications. We present a list from A to Z of twenty-six proposals regarding what a 'good' QCA-based research entails, both with regard to QCA as a research approach and as an analytical technique. Our suggestions are subdivided into three categories: criteria referring to the research stages before, during, and after the analytical moment of data analysis. This listing can be read as a guideline for authors, reviewers, and readers of QCA. Adapted from the source document.

  136. WAGEMANN, Claudius and SCHNEIDER, Carsten Q. (2003), "Fuzzy-Set Qualitative Comparative Analysis (Fs/QCA). Ein Zwei-Stufen-Modul", in PICKEL, Susanne, PICKEL, Gert, LAUTH, Hans-Joachim, and JAHN, Detlef (eds), Vergleichende Politikwissenschaftliche Methoden. Neue Entwicklungen und Diskussionen, Wiesbaden, Westdeutscher Verlag, pp. 105-134.

  137. ---------- (2003), "Fuzzy Set Qualitative Comparative Analysis (fs/QCA): ein Zweischritt-Modul", in PICKEL, Susanne, PICKEL, Gert, LAUTH, Hans-Joachim, and JAHN, Detlef, 'Titel noch nicht bekannt' (title still unknown)Westdeutscher Verlag,
    Abstract: Zusammenfassung Dieser Beitrag untersucht, wie ‚Fuzzy Set Qualitative Comparative Analysis’ (fs/QCA) dazu beitragen kann, kausale Schlüsse in vergleichenden sozialwissenschaftlichen Analysen zu ziehen. Unser Ausgangspunkt ist, dass fs/QCA gegenüber herkömmlichen statistischen Verfahren und (vergleichenden) Fallstudien sowohl in Bezug auf die Berücksichtigung von kausaler Komplexität und Kontextabhängigkeit als auch auf die Generalisierbarkeit der Ergebnisse entscheidende Vorteile besitzt. Kernpunkt unserer Argumentation ist, dass die durch die Anwendung von fs/QCA beschreibbaren kausalen Effekte nicht notwendigerweise linear, additiv und unifinal sind. In der Folge schlagen wir ein Zweischritt-fs/QCA Modul vor, welches die Anwendungsmöglichkeiten von fs/QCA in tatsächlichen Forschungssituationen verbessert. Dieser Ansatz greift sowohl auf die deduktive als auch die induktive Forschungslogik zurück, und verbindet ‚ferne‘ und ‚nahe‘ kausale Faktoren miteinander. In der Folge können so ‚Theorien mittlerer Reichweite’ herausgebildet werden. Wir illustrieren unseren methodischen Ansatz mit einem Beispiel aus der Forschung zur Konsolidierung von Demokratien.

  138. ---------- (2007), "Standards of Good Practice in Qualitative Comparative Analysis (QCA) and Fuzzy-Sets", COMPASSS Working Paper, 51, 35p. (http://www.compasss.org/WagemannSchneider2007.pdf)
    Abstract: Over the last couple of years, we witness an increasing curiosity for a methodological family, generally identified with its acronym, 'QCA'. This stands for 'Qualitative Comparative Analysis', which was introduced for the first time to a wider public by the American social scientist Charles Ragin in 1987 (1987). Since then, QCA has been modified, extended and improved several times (Ragin 2000; Ragin 2003b; Ragin 2006a Ragin 2006b; and Ragin and Sonnett 2004). These developments have contributed to a better applicability of QCA to empirical social scientific research questions and to its prominence within the discipline. In this article, we will, first, present the 'state of the art' of QCA and will introduce both its basic principles and the different variants of this group of 'Configurational Comparative Methods' (a term coined by Rihoux and Ragin 2007a, which might probably substitute ‘Qualitative Comparative Analysis’ in the long run). After this, we will propose a list of criteria for a 'good' QCA analysis. We hope that our contribution can be a guideline for QCA users as to which aspects have to be considered when carrying out QCA analyses in order to render them not only technically correct, but also to make the best out of the analytically relevant information one can generate with QCA. Furthermore, the standard of good practice which we propose can also be a helpful instrument for readers and commentators when they have to evaluate empirical analyses based on QCA techniques.

  139. WALKUP, J. (2003), "Book Review : Fuzzy-Set Social Science", Evaluation and Program Planning, 26, 41-44.

  140. ZADEH, Lofti A. (1965), "Fuzzy-Sets", Information and Control, 8, 338-353.

  141. ZADEH, Lofti A. (1968), "Fuzzy Algorithms", Information and Control, 12, 99-102.

  142. ---------- (2002), "From Computing With Numbers to Computing With Words", Applied Mathematics, 12, 2, 307-332.