Chained computerized adaptive testing for the Force Concept Inventory

TL;DR

This paper introduces Chain-CAT, a novel adaptive testing method that links multiple short assessments during a course to monitor student understanding more frequently and efficiently than traditional pre-post tests.

Contribution

The paper develops and evaluates Chain-CAT, a new adaptive testing algorithm that improves efficiency by linking sequential assessments using collateral information.

Findings

Collateral information enhances test efficiency.

Overall test length can be shorter than traditional pre-post assessments.

Chain-CAT achieves comparable efficiency with only 5-item tests repeated 9 times.

Abstract

Although conceptual assessment tests are commonly administered at the beginning and end of a semester, this pre-post approach has inherent limitations. Specifically, education researchers and instructors have limited ability to observe the progression of student conceptual understanding throughout the course. Furthermore, instructors are limited in the usefulness of the feedback they can give to the students involved. To address these challenges, we propose an alternative approach that leverages computerized adaptive testing (CAT) and increasing the frequency of CAT-based assessments during the course, while reducing the test length per administration, thus keeping or decreasing the total number of test items administered throughout the course. The feasibility of this idea depends on how far the test length per administration can be reduced without compromising the test accuracy and precision. Specifically, the overall test length is desired to be shorter than when the full assessment is administered as a pretest and subsequent post-test. To achieve this goal, we developed a CAT algorithm that we call Chain-CAT. This algorithm sequentially links the results of each CAT administration using collateral information. We developed the Chain-CAT algorithm using the items of the Force Concept Inventory (FCI) and analyzed the efficiency by numerical simulations. We found that collateral information significantly improved the test efficiency, and the overall test length could be shorter than the pre-post method. Without constraints for item balancing and exposure control, simulation results indicated that the efficiency of Chain-CAT is comparable to that of the pre-post method even if the length of each CAT administration is only 5 items and the CAT is administered 9 times throughout the semester. (To continue, see text.)