The Psychometric Evaluation of a Summative Multimedia-Based Performance Assessment

In this article, a case study on the design, development, and evaluation of a multimedia-based performance assessment (MBPA) for measuring confined space guards' skills is presented. A confined space guard (CSG) supervises operations that are carried out in a confined space (e.g. a tank or silo). Currently, individuals who want to become a certified CSG in The Netherlands have to participate in a one day training program and have to pass both a knowledge-based MC test and a practice-based performance-based assessment (PBA). Our goal is to measure the skills that are currently being assessed through the PBA, with the MBPA. We first discuss the design and development of the MBPA. Secondly, we present an empirical study which was used for assessing the quality of our measurement instrument. A representative sample of 55 CSG students, who had just completed the one day training program, has subsequently performed in the MC test, and then, depending on the condition they were assigned, the PBA or the MBPA. We report the psychometric properties of the MBPA. Furthermore, using correlations and regression analysis, we make an empirical comparison between students' scores on the PBA and the MBPA. The results show that students' scores on the PBA and the MBPA are significantly correlated and that students' MBPA score is a good predictor for their score on the PBA. In the discussion, we provide implications and directions for future research and practice into the field of MBPA.