If Generalization is the Grail, Practical Relevance is the Nirvana: Considerations from the Contribution of Psychological Science of Memory to Law

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.