WIP: Psychometric Analysis of Electric Circuit Concepts Diagnostic (ECCD) Basic Test Items: A Classical Test Theory Approach

Concept inventories are diagnostic instruments designed to assess student understanding and identify common misconceptions in a specific domain or discipline. They consist of multiple-choice questions or tasks that target key concepts and principles in the subject matter. The ECCD was developed to diagnose student misconceptions of electric concepts like power, energy, and potential difference. For concept inventories to be effective in measuring misconceptions, the items on the test must possess two essential qualities: validity and reliability. We administered the ECCD to 270 undergraduate engineering students in the summer and fall of 2023 and the test items are examined using the classical test theory framework. Results from the analysis show that most of the items on the test perform well in terms of item difficulty, item discrimination, and reliability. Findings from this work-in-progress analysis pointed to a few items that might need revision or be discarded on the final test. The implication of these findings is also reported.