Internal Validity Issues in Implicit Learning Research

With Dr. Rebecca Sachs, Virginia International University, and Dr. Phillip Hamrick, Kent State University.

Having confidence in research depends upon a study’s internal validity (i.e., whether the study’s results reflect what the study purported to investigate). While issues of internal validity warrant serious conversation in several areas of SLA, there has recently been an especially active investigation of internal validity in the area of implicit learning (e.g., Hamrick & Sachs, 2017; Leow & Hama, 2013; Rebuschat, Hamrick, Riestenberg, Sachs, & Ziegler, 2015; Sachs, Hamrick, McCormick, & Leow, 2018).

In this talk, we review several strands of our own research that have focused on improving internal validity in implicit learning and related research areas. In particular, we highlight important methodological considerations for (a) establishing evidence that genuine learning has happened in a study, (b) demonstrating evidence of implicit and explicit knowledge using subjective measures of awareness, and (c) employing reaction time methods in SLA. In doing so, we also demonstrate how some of these threats to internal validity extend beyond implicit learning research. We conclude by discussing how many of these issues can be identified and potentially alleviated through methods such as triangulation and the incorporation of individual difference measures.