This guide offers a comprehensive handbook to scientific research methodology and experimental design, specifically for novice MA and PhD researchers in Education and Language Learning (TESOL/TEFL). It establishes scientific research as a systematic, objective inquiry focused on identifying cause-and-effect relationships through empirical data.…

Selection bias is problematic when evaluating the effects of postsecondary interventions on college students, and can lead to biased estimates of program effects. While instrumental variables can be used to account for endogeneity due to self-selection, current practice requires that all five assumptions of instrumental variables be met in order…

Educators continue to have difficulty reforming English curricula in ways that better serve the needs of second language learners. This difficulty is perpetuated, in part, by the inability to predict how such changes will affect morphosyntactic development. To date, ESL research has failed to effectively ascertain how multiple causes influence the…