Logic of Qualitative Methods (Modules 1, 5, 9)
Monday, June 15; Tuesday, June 16; Wednesday, June 17
Eggers Hall, Room 032
James Mahoney (Northwestern University), Gary Goertz (Independent Researcher)
These three modules discuss qualitative methodology by using logic as a foundation. They cover many classic and standard topics of qualitative methodology: necessary and sufficient conditions, small-N comparative methods, sequence analysis, concepts, typologies, process tracing, causal mechanisms, counterfactuals, critical junctures, sequences, narrative, and case selection. The modules also provide the basic tools for a complete research design for a Ph.D. dissertation or book project.
The first module (led by James Mahoney) provides an introduction to logic and set theory, summarizes classic small-N methodologies, discusses a regularity theory of causality, and presents counterfactual analysis as a tool for evaluating hypotheses. The second module (led jointly by Gary Goertz and James Mahoney) focuses on concepts, within-case causal analysis, and temporality and sequence analysis. The final module (led by Gary Goertz) consists of three sessions on Large-N Qualitative Analysis (LNQA). This methodology involves process tracing, i.e., within-case causal inference, with a goal of systematic causal generalization across the cases.
Participants may enter the module sequence after it has begun.
The Set-Theoretic Foundations of Qualitative Research (M1, June 15)
This module discusses qualitative methodology and research from the perspective of logic and set theory. It begins with an introduction to logic and set theory, focusing on how logical ideas underpin qualitative research in practice. A central theme is that much can be gained from using logic explicitly rather than implicitly. In the second session, James Mahoney draws on his own current research on Radical Political Transformations to illustrate the use of various qualitative methods. He emphasizes the ways in which a wide variety of methods can be understood and enhanced through set theory. Finally, the third section focuses on counterfactual analysis, which is a crucial methodology for within-case causal analysis in qualitative research. Several tools for carrying out counterfactual analysis are discussed.
8:45am - 10:15am – Introduction to Logic and Set Theory
James Mahoney
This session first provides a selective introduction to the use of logic and set theory in qualitative research. The key topics covered include necessary, sufficient, and INUS conditions; set diagrams; and statistics versus logic. The second part uses the ideas from the first part to introduce a modern regularity theory of causality. This theory builds from the idea that causality is a recurrent spatial and temporal relationship between X and Y.
Required reading:
- Gary Goertz and James Mahoney, “Introduction,” “Mathematical Prelude,” “Causes of Effects versus Effects of Causes” and “Causal Models” in A Tale of Two Cultures: Qualitative and Quantitative Research in the Social Sciences (Princeton: Princeton University Press, 2012), pp. 1-63.
Suggested reading:
- James Mahoney and Laura Acosta, “A Regularity Theory of Causality for the Social Sciences.” Quality and Quantity 56 (2022), pp. 2001-2022.
1:30pm - 3:00pm – Qualitative Methods in Practice
James Mahoney
This session introduces classic qualitative methodologies through an explicit examination of James Mahoney’s new work on Radical Political Transformations in world history. The specific methodological tools discussed include the methods of agreement and difference, typological theory, set-theoretical analysis, sequence analysis, and narrative presentation. Mahoney illustrates the logic of each of these methods by using his new work as a concrete example.
Required readings:
James Mahoney and Qin Huang, “Radical Political Transformations in World History: Concepts, Cases, and Patterns,” Manuscript, Northwestern University 2026.
James Mahoney and Rachel Sweet Vanderpoel, “Set Diagrams and Qualitative Research,” Comparative Political Studies 48:1 (January 2015), pp. 65-100.
3:30pm - 5:00pm – Counterfactual Analysis
James Mahoney
This session considers the use of counterfactual analysis as a tool for evaluating complex causal theories at the level of individual cases. The session focuses on the evaluation of necessary condition hypotheses with counterfactual analysis. The discussion includes several concrete examples to illustrate how counterfactual analysis is a crucial part of process tracing and hypothesis evaluation in qualitative research.
Required readings:
Jack S. Levy, “Counterfactuals and Case Studies,” in Janet M. Box-Steffensmeier, Henry E. Brady, and David Collier, eds., The Oxford Handbook of Political Methodology (Oxford: Oxford University Press, 2008), pp. 627-644.
James Mahoney and Rodrigo Barrenechea, “The Logic of Counterfactual Analysis in Case-Study Explanation,” British Journal of Sociology 70:1 (2019), pp. 306-338.
Suggested readings:
Frank P. Harvey, “President Al Gore and the 2003 Iraq War: A Counterfactual Test of Conventional Wisdom,” Canadian Journal of Political Science 45:1 (2012), pp. 1-32.
Luis Schenoni, Sean Braniff, and Jorge Battaglino, “Was the Malvinas/Falklands a Diversionary War? A Prospect-Theory Representation of Argentina’s Decline,” Security Studies 29 (2020), pp. 34-63.
The Logic of Qualitative Research II (M5, June 16)
8:45am - 10:15am – Social Science Concepts
Gary Goertz
This session provides basic guidelines for the construction and evaluation of concepts. It provides a framework for dealing with complex concepts, which are typical in much social science research, as well as the popular construction of global indices, such as HDI, poverty measures, and the like generated by IGOs, NGOs, the EU, World Bank, and so on. The session also covers common advice for building conceptual typologies.
Required reading:
- Gary Goertz, Social Science Concepts, revised ed. (Princeton: Princeton University Press, 2020), chapter 2 pages 26-35, chapter 3.
Suggested reading:
- Gary Goertz 2020, Social Science Concepts, chapter 1, rest of chapter 2, and chapter 8 on typologies.
1:30pm - 3:00pm – Within-Case Causal Analysis and Process Tracing
Gary Goertz and James Mahoney
This module focuses on process tracing as within-case causal inference. Central to qualitative methods is doing case studies that make clear causal claims — ideally based in causal model-mechanism figures — and then using information about the case to justify the causal claims about the individual case. Here we provide a framework for thinking about within-case causal inference, mechanisms and theory, and the topic of evidence aggregation. Particularly important are ways to aggregate different kinds of evidence into an overall conclusion. We provide an extended example of process tracing from James Mahoney’s new research on Radical Political Transformations. Mahoney discusses how he uses process tracing to assess hypotheses linked to two competing theories.
Required reading:
- Gary Goertz and Stephen Haggard, Large-N Qualitative Analysis (LNQA) (Princeton: Princeton University Press, 2027), pp. 101-107 from chapter 5 and Appendix B.
Suggested readings:
David Collier, “Understanding Process Tracing.” PS: Political Science and Politics 44(2011): 823–830.
David Waldner. “What Makes Process Tracing Good? Causal Mechanisms, Causal Inference, and the Completeness Standard in Comparative Politics.” In Process Tracing: From Metaphor to Analytic Tool, edited by Andrew Bennett and Jeffrey T. Checkel, 126–52. Cambridge: Cambridge University Press, 2015.
3:30pm - 5:00pm – Critical Events, Path Dependence, and Sequence Analysis
James Mahoney
This session introduces the methodology of critical event analysis and discusses temporal issues related to critical junctures, sequence analysis, and path dependence. A major goal is to introduce concrete tools for identifying and analyzing causally important events within history. In addition, a variety of issues related temporal analysis are addressed, including alternative definitions of path dependence and the relationship between narrative and sequence analysis.
Required reading:
- Laura García-Montoya and James Mahoney, “Critical Event Analysis in Case Study Research.” Sociological Methods and Research 52:1 (2023), pp. 480-524.
Suggested readings:
James Mahoney, Erin Kimball, and Kendra Koivu, “The Logic of Historical Explanation in the Social Sciences,” Comparative Political Studies 42:1 (January 2009), pp. 114-146.
James Mahoney and Daniel Schensul, “Historical Context and Path Dependence,” in Robert E. Goodin and Charles Tilly, eds., Oxford Handbook of Contextual Political Analysis (Oxford: Oxford University Press, 2006).
Large-N Qualitative Analysis (LNQA) (M9, June 17)
8:45am - 10:15am – An Introduction to LNQA
Gary Goertz
The first module in the LNQA modules provides an overview of the basic methodology. The goal of the methodology is to generate valid generalizations where causal inference rests on within-case causal inference in individual cases. The basic components of LNQA include defining the scope of the generalization, thinking about regularities (particularly in a set theoretic manner), being explicit about the causal mechanism, and then doing within-case causal inference. The end result is a valid generalization where causal inference is based on within-case analysis as opposed to cross-case analysis.
Required readings:
Gary Goertz and Stephen Haggard, Large-N Qualitative Analysis (LNQA) (Princeton: Princeton University Press, 2027), Introduction.
Gary Goertz and Stephen Haggard, “Large-N Qualitative Analysis (LNQA).” Perspectives on Politics 2 (2023):1221-1239.
Suggested reading:
- Gary Goertz and Stephen Haggard, Large-N Qualitative Analysis (LNQA) (Princeton: Princeton University Press, 2027), chapters 2-6.
1:30pm - 3:00pm – Theorizing and Diagraming Causal Theories and Mechanisms
Gary Goertz
LNQA is a theory-intensive and causal mechanism-intensive methodology. In order to do process tracing successfully, one needs a clear theory and mechanism. In addition, a clear theory and mechanism is essential for defining the scope of the generalization. The best way to think about, do, and present causal mechanisms is via figures. This module constitutes an introduction not only to doing mechanism figures but also to theorizing in general.
Required reading:
- Gary Goertz and Stephen Haggard, Large-N Qualitative Analysis (LNQA) (Princeton: Princeton University Press, 2027), chapter 5.
3:30pm - 5:00pm – Multimethod-LNQA (M-LNQA)
Gary Goertz
Multimethod research has become a standard practice within comparative politics and international relations. Typically, this means combining case studies with statistical analysis. Multimethod LNQA (M-LNQA) presents a new and quite different approach for how to do this. It takes the basic apparatus of regular LNQA and applies it in the context of an existing statistical analysis. Unlike traditional approaches, causal inference with M-LNQA not only relies on the statistical analysis but also the systematic within-case analysis from LNQA. In this way, the methodology provides a novel approach to dealing with issues of causal inference with observational data. The module presents the basic outline of the methodology using a recent analysis (Leiziger et al. 2025) on ethnic group grievances and civil war occurrence.
Required readings:
Gary Goertz and Stephen Haggard, Large-N Qualitative Analysis (LNQA) (Princeton: Princeton University Press, 2027), chapter 10.
Leipziger, Lasse Egendal, Lasse Lykke Rørbæk, and Svend-Erik Skaaning. “Does Ethnopolitical Exclusion Cause Civil War Onset via Grievances? Evidence from 15 Case Studies.” Perspectives on Politics 23 (2025): 1–18.