Judith Glaesser

Using case‐based approaches to analyse large datasets: a comparison of Ragin’s fsQCA and fuzzy cluster analysis

The paper undertakes a comparison of Ragin’s fuzzy set Qualitative Comparative Analysis with cluster analysis. After describing key features of both methods, it uses a simple invented example to illustrate an important algorithmic difference in the way in which these methods classify cases. It then examines the consequences of this difference via analyses of data previously calibrated as fuzzy sets. The data, taken from the National Child Development Study, concern educational achievement, social class, ability and gender. The classifications produced by fsQCA and fuzzy cluster analysis (FCA) are compared and the reasons for the observed differences between them are discussed. The predictive power of both methods is also compared, employing both correlational and set theoretic comparisons, using highest qualification achieved as the outcome. In the main, using the real data, the two methods are found to produce similar results. A final discussion considers the generalisability or otherwise of this finding.

Just How Flexible Is the German Selective Secondary School System? A Configurational Analysis.

School systems may be usefully characterized according to Turner’s proposed ideal types of sponsored and contest mobility. Germany is a critical case with respect to this typology because its secondary school system is stratified and selective, and yet it offers the opportunity for upward and downward mobility. Drawing on an analysis of a German longitudinal dataset, this paper addresses the question of flexibility or rigidity of the school system, exploring the ways in which factors other than pupils’ ability influence selection processes within that system. Both academic ability and ascriptive factors act together to facilitate or hinder changes of academic routes within the school system. The methodological focus of the paper is on the introduction to an innovative method, Charles Ragin’s Qualitative Comparative Analysis, a method based on set theory. It involves the identification of necessary and sufficient conditions for a given outcome, taking conjunctions of causal conditions into account.

How Has Educational Expansion Changed the Necessary and Sufficient Conditions for Achieving Professional, Managerial and Technical Class Positions in Britain? a Configurational Analysis

This paper, whose purpose is both substantive and methodological, focuses on changes over a nine year period, drawing on data from two British birth cohorts (individuals born in 1958 and 1970), and, substantively, employs set theoretic methods to explore the extent to which an upward shift in qualifications achieved led to any reduction in the roles class and gender played in the achievement of professional, managerial and technical (PMT) social class destinations in early adulthood. Our methodological purpose is to illustrate how a counterfactual modelling approach can be used together with Ragins set theoretic methods to provide an alternative way of analysing relationships in this area. We draw on earlier work exploring the extent to which educational achievement was ‘meritocratic’ with respect to ability for these cohorts (Cooper 2005, 2006). Our configurational account of the causal pathways to various class destinations is set against the background of a simple model of ‘meritocracy’ (allocation to available class positions by qualifications alone taking account of the empirical marginal distributions). This model allows us to specify, counterfactually, what qualifications would have represented necessary and sufficient conditions in our modelled meritocracy for reaching the PMT class. By comparison of these conditions with the empirically derived necessary and sufficient conditions for achieving these outcomes (using Ragin et als fs/QCA software) we show that while allocation processes were far from meritocratic in both cohorts, there were some changes in the way both class and gender combined with qualifications as conditions for destinations. We also show that Ragins configurational methods, focussing on holistically-conceived cases and conjunctural causation rather than on the net effects of independent variables, provide a useful analytic technique for capturing relationships in this field.

Using Rational Action Theory and Bourdieu’s Habitus Theory Together to Account for Educational Decision-making in England and Germany

Both Rational Action Theory (RAT) and Bourdieu’s habitus theory are employed to explain educational decision-making. RAT assumes that decision-making involves cost-benefit analysis, while habitus theory sees educational pathways as shaped by dispositions reflecting familial class of origin. These theories are often seen as conflicting, but we argue that they can fruitfully be used together. Proponents of these theories often employ different methods. RAT advocates usually employ survey data, while those favouring habitus theory often use case studies. If cost-benefit reasoning does partly explain educational decision-making, then we should expect to find evidence of it at the micro-level. Drawing on interviews conducted in Germany and England, we show that young people do indeed talk about their educational choices in ways which fit RAT accounts. Their class-based habitus often, however, provides upper and lower boundaries for their aspirations, thus conditioning the nature of the cost-benefit analysis entering into decision-making.

Underlying success in open‐ended investigations in science: using qualitative comparative analysis to identify necessary and sufficient conditions

Both substantive (i.e. factual knowledge, concepts, laws and theories) and procedural knowledge (understanding and applying concepts such as reliability and validity, measurement and calibration, data collection, measurement error, the ability to interpret evidence and the like) are involved in carrying out an open‐ended science investigation. There is some debate as to whether procedural understanding is of little importance compared to substantive understanding or whether – and this is the view we take – procedural ideas can and should be taught explicitly. We present here findings from a study of undergraduate students who took a module which specifically taught procedural ideas. We employ an innovative method, Charles Ragin’s Qualitative Comparative Analysis (QCA), which involves the analysis of necessary and sufficient conditions and conjunctions of causes. Findings from a comparison of the students’ performance before and after the teaching and from QCA imply that procedural understanding was indeed a necessary condition for carrying out an open‐ended investigation. It was also sufficient when combined with either substantive understanding, prior attainment or both.

Gender, parental education, and ability: their interacting roles in predicting GCSE success

We investigate the relations between gender, parental education, ability, and educational achievement in Britain, focusing on the way in which gender and parental education interact with ability to contribute to a pupil’s obtaining secondary school qualifications. This allows us to provide evidence relevant to claims concerning the effects of differences in the way in which working- and middle-class familial cultures interact with gender-specific behaviour in school. Given the configurational nature of the processes likely to be involved, we employ Ragin’s Qualitative Comparative Analysis as our method. We find that, in both academically selective and non-selective schools, high ability is a quasi-sufficient condition for obtaining certain levels of qualification, but that at lower levels of ability, either being female or having highly educated parents (or both) have to be present, too. Boys without highly educated parents perform less well than girls from a similar background.

Exploring the consequences of a recalibration of causal conditions when assessing sufficiency with fuzzy set QCA

The use of Charles Ragin’s Qualitative Comparative Analysis (QCA) is increasing in the social sciences. However, some of its characteristics, especially those of its fuzzy set variant, are still not well understood by users. QCA, a set theoretic method, aims to describe, in a Boolean form, the configurations of conditions that are necessary and/or sufficient for some outcome. The calibration of set memberships is a central feature. We discuss how two alternative calibrations of a condition affect the assessment of consistency with sufficiency. Using first an abstract example and then an empirical one from the sociology of education, we explain why “stricter” calibration of conditions results in higher consistency with sufficiency. We demonstrate that conventional truth table analysis is not an ideal way to compare the analytic consequences of alternative calibrations and therefore employ an alternative which allows a more direct comparison of consistency indices while keeping comparative configurational contexts intact.

Exploring the robustness of set theoretic findings from a large n fsQCA: an illustration from the sociology of education

Ragin’s Qualitative Comparative Analysis (QCA) is often used with small to medium samples where the researcher has good case knowledge. Employing it to analyse large survey datasets, without in-depth case knowledge, raises new challenges. We present ways of addressing these challenges. We first report a single QCA result from a configurational analysis of the British National Child Development Study dataset (highest educational qualification as a set theoretic function of social class, sex and ability). We then address the robustness of our analysis by employing Duşa and Thiem’s R QCA package to explore the consequences of (i) changing fuzzy set theoretic calibrations of ability, (ii) simulating errors in measuring ability and (iii) changing thresholds for assessing the quasi-sufficiency of causal configurations for educational achievement. We also consider how the analysis behaves under simulated re-sampling, using bootstrapping. The paper offers suggested methods to others wishing to use QCA with large n data.

Selecting Cases for in-Depth Study from a Survey Dataset: An Application of Ragin's Configurational Methods

While ‘establishing the phenomena’, to use Mertons phrase, is an important part of the sociological enterprise, in then accounting for such empirical regularities, theoretical models are required to understand causal processes. Both regression analysis and configurational methods applied to large datasets can establish patterns of relationships. Following a realist view, we assume that causal mechanisms have generated such patterns, and sound theoretical models are required to understand them. In-depth case studies can contribute to advancing such causal knowledge. We describe how, in the particular context of the configurational mode of analysis that characterises Ragins Qualitative Comparative Analysis (QCA), we have selected individuals for in-depth study with the eventual purpose of advancing causal or explanatory understanding of conjunctural empirical regularities concerning educational careers. While forms of regression analysis seek to establish the net effects of ‘independent’ variables, QCA, employing Boolean algebra, analyses the conjunctions of conditions sufficient and/or necessary for an outcome to occur. QCA aims to preserve, holistically, the features of cases and is therefore well-suited to case selection. We use QCA both to undertake an initial large scale cross-case analysis and to subsequently select cases to develop theoretical understanding via within-case analysis. Using QCAs measures of consistency with relations of sufficiency and necessity, we can classify cases as typical and deviant, with these two types of cases playing different roles in testing and developing theory. Drawing on analyses of the German SOEP dataset undertaken as part of a larger study which is applying case-based configurational methods to English and German survey datasets while undertaking subsequent in-depth interviews with selected cases, we demonstrate how QCA can be used to select cases for interview in a systematic and theoretically informed manner.

Educational achievement in selective and comprehensive local education authorities: a configurational analysis

Selective and comprehensive school systems vary in both the degree and timing of selection. To study the consequences of such variation, cross-national comparisons are usually undertaken. Given that cultural differences between countries affect pathways and outcomes, apportioning causal influence in such studies can be difficult. In 1970s Britain, selective and comprehensive systems coexisted. This enables us to compare the influences of organisational arrangements without the complication of national cultural differences. We analyse, for children of various abilities, while taking account of gender and class, the effect on achievement of experiencing comprehensive or selective schooling. Assuming that contextual and individual factors work conjuncturally in producing outcomes, we employ Ragins configurational Qualitative Comparative Analysis. By treating cases in the National Child Development Study as configurations of factors, we are able to analyse the sufficient and necessary conditions for achievement. We find that system differences affect only some high-ability childrens educational outcomes.