Ensuring internal validity in quantitative research requires, among other conditions, reliable instrumentation. Unfortunately, however, second language (L2) researchers often fail to report and even more often fail to interpret reliability estimates beyond generic benchmarks for acceptability. As a means to guide interpretations of such estimates,…

This meta-analytic study provides a systematic statistical synthesis of the effects of output tasks on second or foreign incidental vocabulary learning. A total of 12 studies were included in this meta-analysis. Five mediator variables were examined: design quality, types of output task, time on task, genres of text, and text-target word ratios.…