If generalization is the grail, practical relevance is the nirvana: Considerations from the contribution of psychological science of memory to law.

Abstract

In this commentary, we argue that besides focusing on generalization, sufficient attention must be invested in the practical relevance of psychological and applied memory research. That is, memory research is frequently used to address real-life questions. In the area of psychology and law, memory scientists are sometimes asked by court to provide expert opinion about, for example, the validity of witness testimony. When doing so, they refer to applied memory research to support their conclusion on whether or not a statement is valid. But when can applied memory research meaningfully inform legal cases? Memory scientists can best know the practical relevance of research by considering the smallest effect size of interest in a given domain. Applied memory research has generally failed to consider the importance of the smallest effect size of interest and instead relies uncritically on benchmarks of effect sizes (e.g., small, medium, large). We demonstrate how memory scientists can set the smallest effect size of interest, and we provide an example in the area of false memory. We argue that psychological science can best contribute to law when memory scientists make use of the smallest effect size of interest.

Recognizing limits on the generalizability of findings of psychological science research.

“…One such observation is that, as a field, we do not do a very good job of distinguishing between statistical significance and practical (or I will add, theoretical) relevance. Otgaar et al (2023) make this point in the realm of eyewitness testimony and forensic applications more broadly. They note that sometimes in forensic applications, small differences, such as a single forgotten or incorrect detail, can have profound implications for evaluation of the veracity of eyewitness identifications or the outcome of legal proceedings, for example.…”

“…Across the commentaries, there is substantial convergence with the arguments in the target article (as well as in Yarkoni, 2022) that generalizability is a hallmark of psychological science and that at present, the field falls short of achieving this goal. The authors of the commentaries also highlight that these issues are especially critical when we have in mind not just behavior in the laboratory but in the world beyond it—that is, as we attempt to apply the findings of our research to classrooms, workplaces, and courtrooms, to name a few (Mitchell & Shivde, 2023; Otgaar et al, 2023). They reinforce the need for attention to cultural background, individual variability, methodological variations, and other sources of variance between and among participants that may limit generalizability of findings (Peterson, 2023; Prather, 2023).…”

“…The most prominent of these differences emerges along the lines of the proverbial argument regarding which goals should dominate in psychological science: those of application or those of theory. Otgaar et al (2023) make the argument that the practical relevance of psychological research is paramount. Indeed, they criticize the target article for not paying sufficient attention to this issue in the discussion of generalizability.…”

“…We can and should take the size of effect into consideration, especially as we move from the laboratory to the classroom or courtroom. And as Otgaar et al (2023) remind us, the effect need not be large to be of consequence (though small effects may be especially likely to fail tests for generalization). Effect sizes also have theoretical implications.…”

“…Even when effects generalize across populations and stimuli, for example, they may mean something different in different contexts. Otgaar et al (2023) made this point regarding applications of laboratory findings to forensic contexts. We also may think about different implications of the same finding to different populations.…”