This article constitutes the first empirical assessment of methodological quality in second language acquisition (SLA). We surveyed a corpus of 174 studies (N = 7,951) within the tradition of research on second-language interaction, one of the longest and most influential traditions of inquiry in SLA. Each report was coded for methodological features, statistical analyses, and reporting practices associated with research quality, and the resulting data were examined both cumulatively and over time. The findings indicate not only strengths and weaknesses but a possible relationship between study quality and outcomes; improvements over time and methodological trends are also noted. In addition to providing direction for future research and research practices, the study's findings are discussed and contextualized within the research culture of SLA.