Measuring Implicit and Explicit Knowledge in Second Language Research

This article reviews three types of measures which have been widely used in psychological research to assess the conscious or unconscious status of knowledge: retrospective verbal reports, direct and indirect tests, and subjective measures. The goal is to make these techniques available to a wide audience of second language (L2) researchers and to offer suggestions for their sound use in order to promote the study of implicit L2 learning. Each section begins with a brief definition of what it means to have acquired unconscious (implicit) knowledge according to the measure in question. This is followed by a description of representative studies that illustrate how the technique has been used and by a discussion of its limitations. Each section concludes with specific guidelines on how to apply the respective measure to the investigation of implicit and explicit L2 learning.