Evaluating an electricity and magnetism assessment tool: Brief electricity and magnetism assessment

The Brief Electricity and Magnetism Assessment (BEMA), developed by Chabay and Sherwood, was designed to assess student understanding of basic electricity and magnetism concepts covered in college-level calculus-based introductory physics courses. To evaluate the reliability and discriminatory power of this assessment tool, we performed statistical tests focusing both on item analyses (item difficulty index, item discrimination index, and item point biserial coefficient) and on the entire test (test reliability and Ferguson's delta). The results indicate that BEMA is a reliable assessment tool.