Quantitative Research Methods, Study Quality, and Outcomes: The Case of Interaction Research


  • Editor's Note. This systematic review article is a contribution by invitation of the new journal editor, Lourdes Ortega, and was peer reviewed by three experts.

  • This article is based on a plenary delivered at Second Language Research Forum, 2009 (Gass) with the title Oh what a tangled web we weave and on a qualifying research paper by Plonsky (2010). We are grateful to Shawn Loewen for helpful and significant feedback on the qualifying research paper by Plonsky. Our thanks also go to Allison Dovi and Cassandra Shanbaum for their assistance with coding. All errors that remain are our own.

concerning this article should be addressed to Luke Plonsky, Second Language Studies, Michigan State University, 101 UPLA, East Lansing, MI 48824. Internet: plonskyl@msu.edu


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.