Sorting the File Drawer: A Typology for Describing Unpublished Studies.

A typology of unpublished studies is presented to describe various types of unpublished studies and the reasons for their nonpublication. Reasons for nonpublication are classified by whether they stem from an awareness of the study results (result-dependent reasons) or not (result-independent reasons) and whether the reasons affect the publication decisions of individual researchers or reviewers/editors. I argue that result-independent reasons for nonpublication are less likely to introduce motivated reasoning into the publication decision process than are result-dependent reasons. I also argue that some reasons for nonpublication would produce beneficial as opposed to problematic publication bias. The typology of unpublished studies provides a descriptive scheme that can facilitate understanding of the population of study results across the field of psychology, within subdisciplines of psychology, or within specific psychology research domains. The typology also offers insight into different publication biases and research-dissemination practices and can guide individual researchers in organizing their own file drawers of unpublished studies.