TASK SPECIFICATION CHART: A KEY TO A BETTER UNDERSTANDING OF TEST RESULTS

A task specification chart (TSC) that integrates the content facets and the procedural steps of a specified task is suggested as a tool for designing a test and for interpreting its results. An instructional unit for adding and subtracting fractions was used to demonstrate the design and application of the TSC. To evaluate its efficacy, a test based on the TSC was administered to two independent samples. Accounts of the variance of item difficulty indices and errors in students' responses were used as the criteria for this evaluation. The results indicated that a very high percentage of variance in item difficulty indices was accounted for by item characteristics representing different task components. The typology of errors constructed on the basis of the TSC proved to be an efficient tool for identifying erroneous rules of operation underlying students' response patterns on the test.