Qualitative Comparative Analysis and robust sufficiency

Some methodologists take the search target of Qualitative Comparative Analysis (QCA) to be causal INUS-conditions, others contend that QCA should instead be used to search for some form of sufficiency that is more substantive than mere Boolean sufficiency. While the notion of an INUS-condition has a long and uncontroversial definitional history, Adrian Dusa, in a recent paper, is the first to explicitly define a notion of substantive sufficiency, which he labels robust sufficiency. Dusa’s definition, however, is vacuous in real-life research contexts. As an alternative, the first part of this paper non-vacuously defines robust sufficiency and supplies a corresponding notion of minimality, which—I argue—captures Dusa’s conceptual intentions. In the second part, I then report and discuss the results of a series of simulation experiments benchmarking the performance of the different QCA solution types in recovering robust sufficiency and minimality.

Actual Causality in a Logical Setting

We provide a definition of actual causation in the logical framework of the causal calculus, which is based on a causal version of the well-known NESS (or INUS) condition. We compare our definition with other, mainly counterfactual, approaches on standard examples. On the way, we explore general capabilities of the logical representation for structural equation models of causation and beyond.

Evidence-Based Educational Practice

Evidence-based practice (EBP) is a buzzword in contemporary professional debates, for example, in education, medicine, psychiatry, and social policy. It is known as the “what works” agenda, and its focus is on the use of the best available evidence to bring about desirable results or prevent undesirable ones. We immediately see here that EBP is practical in nature, that evidence is thought to play a central role, and also that EBP is deeply causal: we intervene into an already existing practice in order to produce an output or to improve the output. If our intervention brings the results we want, we say that it “works.” How should we understand the causal nature of EBP? Causality is a highly contentious issue in education, and many writers want to banish it altogether. But causation denotes a dynamic relation between factors and is indispensable if one wants to be able to plan the attainment of goals and results. A nuanced and reasonable understanding of causality is therefore necessary to EBP, and this we find in the INUS-condition approach. The nature and function of evidence is much discussed. The evidence in question is supplied by research, as a response to both political and practical demands that educational research should contribute to practice. In general, evidence speaks to the truth value of claims. In the case of EBP, the evidence emanates from randomized controlled trials (RCTs) and presumably speaks to the truth value of claims such as “if we do X, it will lead to result Y.” But what does research evidence really tell us? It is argued here that a positive RCT result will tell you that X worked where the RCT was conducted and that an RCT does not yield general results. Causality and evidence come together in the practitioner perspective. Here we shift from finding causes to using them to bring about desirable results. This puts contextual matters at center stage: will X work in this particular context? It is argued that much heterogeneous contextual evidence is required to make X relevant for new contexts. If EBP is to be a success, research evidence and contextual evidence must be brought together.