Small Samples in Instructed Second Language Acquisition Research

This commentary discusses the issue of small samples in instructed second language acquisition research. We discuss the current state of affairs, and consider the disadvantages of small samples. We also explore other considerations regarding sample size, such as research ethics and ecological validity. We present a range of recommendations for researchers to address the issue of small samples. Recommendations include (a) engaging in sample size planning, (b) opting for appropriate designs and analytical approaches, (c) reporting the constraints that sample size places on the interpretation of findings, and (d) cultivating a culture of collaboration and open science.