Publications & Resources

A Follow-Up Investigation of the Role of Cover Story on the Assessment of Experimental Design Skills

Apr 2003

Corinne Zimmerman and Robert Glaser

Cover story is a potentially relevant factor in the assessment of reasoning and problem solving in science, given repeated demonstration of its effect on laboratory tasks. This study follows up on a preliminary interview study that showed cover story influenced the way students were assessed at the end of an instructional unit. Two main changes characterize the present attempt to replicate earlier findings. First, testing materials were changed so as to reduce the number of possible explanations for the cover story effect, if found. Second, students completed the open-ended assessment in a group classroom setting rather than during individual interviews. There were no performance differences for cover stories that instructed students to design an experiment to test a positive claim (i.e., that coffee grinds are “good” for plants), a negative claim (i.e., that coffee grinds are “bad” for plants), or a neutral control. Observed differences, however, were related to the teacher that students had for the instructional unit. Implications for assessment are discussed.

Zimmerman, C., & Glaser, R. (2003). A followup investigation of the role of cover story on the assessment of experimental design skills (CSE Report 594). Los Angeles: University of California, Los Angeles, National Center for Research on Evaluation, Standards, and Student Testing (CRESST).