Assessing conceptual knowledge using similarity judgments

This study evaluates the validity of a similarity judgments test (SJT) for assessing conceptual knowledge. 89 high school seniors judged the semantic similarity of a set of concepts. The resulting scores are calculated using a correlational approach as well as the MDS and Pathfinder approaches, respectively. The validity of the SJT is estimated by comparing (a) the scores with the test scores resulting from a multiple-choice test, (b) the scores resulting from pre- and post-instruction, and (c) the scores of students with high vs. low expertise. Our results support the validity of the SJT and show that both the correlational and the Pathfinder approach outclass the MDS approach. Recommendations to evaluate the SJT are provided.

► We examine whether a similarity judgments test validly measures conceptual knowledge.
► We employ a correlational approach as well as the Pathfinder and MDS approaches to analyze our test.
► The correlational and Pathfinder approaches outclass the MDS approach.
► The correlational approach shows advantages over the Pathfinder approach.