Outcome-Reporting Bias in Education Research

Outcome reporting bias occurs when primary studies do not include information about all outcomes measured in a study. When studies omit findings on important measures, efforts to synthesize the research using systematic review techniques will be biased and interpretations of individual studies will be incomplete. Outcome reporting bias has been well-documented in medicine, and has been shown to lead to inaccurate assessments of the effects of medical treatments and, in some cases, to omission of reports of harms. This study examines outcome reporting bias in educational research by comparing the reports of educational interventions from dissertations to their published versions. We find that non-significant outcomes were 30% more likely to be omitted from a published study than statistically significant ones