F-type testlets and the effects of feedback and case-specificity.

A novel type of item sets, "f-type" testlets, was recently introduced on the United States Medical Licensing Examination. These testlets contain two or more questions associated with a common clinical scenario. In some cases, as the scenario unfolds, examinees are indirectly provided with feedback about their response to a testlet question. The effects of this format and of the provision of feedback to examinees about their performance are investigated. Examinee behavior is predicted using an item response model, and observed examinee responses are compared with model expectations for f-type testlets. Mean model-data discrepancies among specific examinee groups are compared to study the dependencies across within-testlet items (i.e., case-specificity) and the impact of providing feedback. Findings showed that case-specificity effects were present (on average) for all examinee subgroups except examinees who both responded unsuccessfully to the initial item within an f-type testlet and received feedback. Case-specificity effects were negative for examinees who responded unsuccessfully to the initial testlet item but did not receive feedback. For those who responded successfully to the initial testlet items, case-specificity effects were positive. Results suggest that responses to test questions within an f-type testlet are not independent-even after accounting for examinee proficiency and item characteristics. Case-specificity effects (i.e., dependencies) were observed on average for all examinees except those who both responded unsuccessfully to the initial item within an f-type testlet and received feedback. Research into modeling these effects through the use of more general item response models is recommended.