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 be expected to select the same answer regardless of their ethnicity. However, aboriginals and non-aboriginals 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. The present study used differential bundle functioning (DBF) analyses with cognitive processing theory as the organizing principle to study group differences. Aboriginal and non-aboriginal students were compared on Grade 6 Mathematics, Science, and Social Studies 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 non-aboriginals would occur for those bundles eliciting successive processes. When the bundles were tested, performance differences did not favor aboriginals for simultaneous items or non-aboriginals for successive items. Ability distribution differences between the aboriginal and non-aboriginal samples coupled with small sample sizes for the aboriginal samples were key limitations of the study. Recommendations for future research are presented.