Open educational resources (OERs) provide a potential alternative to costly textbooks and can allow content to be edited and adapted to a variety of classroom environments. At the University of California, Davis, the OER "ChemWiki" project, as part of the greater STEMWiki Hyperlibrary, was developed to supplant traditional post-secondary…

This meta-analysis of 49 comparative studies shows that mastery testing has positive effects on student learning, but the size of effect depends on the stringency of the criterion used and the degree of experimental control. The effects of instructional time, student attitudes, and differences in ability levels are also addressed. (Author/LRW)