Differential Bundle Functioning on Three Achievement Tests: A Comparison of Aboriginal and Non-Aboriginal Examinees.

Items on achievement tests are designed to be equivalent in educational testing situations. That is, the information provided to the student is designed to be the same regardless of the ethnicity of the examinee. As a result, students of equal ability would normally be expected to select the same answer regardless of their ethnicity. However, aboriginals and nonaboriginals may use different cognitive processing skills, and consequently may find items differentially easy or difficult depending on which cognitive processing style is elicited by the item. This study used differential bundle functioning (DBF) analyses with cognitive processing theory as the organizing principle to study group differences. Aboriginal and nonaboriginal students were compared on grade-6 mathematics (956 aboriginal and 2,000 nonaboriginal students), science (480 aboriginal and 2,000 nonaboriginal students), and social studies (971 aboriginal and 2,000 nonaboriginal students) achievement tests. Items on these tests were identified by raters trained in cognitive processing theory as eliciting either simultaneous or successive cognitive processing skills. Items were then grouped and tested for DBF using the statistical program SIBTEST. It was hypothesized that differences favoring aboriginals would occur for those bundles eliciting simultaneous processes, while differences favoring nonaboriginals would occur for those bundles eliciting successive processes. When the bundles were tested, performance differences did not favor aboriginals for simultaneous items nor nonaboriginals for successive items. Ability distribution differences between the aboriginal and nonaboriginal samples coupled with small sample sizes for the aboriginal samples were the key limitations of the study. Recommendations for future research are presented. (Contains 2 tables and 32 references.) (Author/SLD)