Lin Ding
Department of Physics
North Carolina State University

Validating and using two assessment tools-BEMA and an energy test.

BEMA (Brief Electricity and Magnetism Assessment) is a comprehensive E&M 
assessment tool, designed to measure student understanding and retention 
of basic topics covered in the calculus-based introductory E&M courses.[1] 
During the development of BEMA, the item analysis and test analysis were 
performed to validate this assessment tool. The analysis results, as will 
be reported in the talk, indicate that BEMA is a reliable and 
discriminatory test. Based on this finding, BEMA was administered to the 
students recruited from both the traditional and reformed (M&I: Matter & 
Interactions[2]) E&M classes as a post-test in the fall semester of 2004 
at NCSU.  A series of comparisons in the BEMA score between and within the 
two samples of students were carried out. As they will be presented in the 
talk, the results show that students from the M&I classes outperformed 
students from the traditional classes.

As a part of my ongoing research, an energy test for the M&I mechanics 
course is under development. The goal of the energy test, the methodology 
of the test construction, together with the pilot study results will be 
reported. In addition, some interesting issues that have arisen will be 
presented as well, such as question representation.numerical vs. symbolic, 
diagram vs. no diagram, and number of reasoning steps. 

[1] L. Ding, R. Chabay, B. Sherwood, and R. Beichner, Evaluating an 
electricity and magnetism assessment tool: Brief electricity and magnetism 
assessment, Phys. Rev. ST Phys. Educ. Res. 2, 010105 _2006_.

[2] Matter & Interactions I: Modern Mechanics and Matter & Interactions 
II: Electric and Magnetic Interactions. Ruth Chabay & Bruce Sherwood, 
Wiley 2002.