High-stakes examinations assess professionals’ abilities to make correct professional judgments in critical situations. However, it is as important and potentially more important to also assess a professional’s ability to avoid “wrong” actions which can cause adverse events. Adverse events may result from either errors of omission (what was not done that should have been done) or errors of commission (what was done that should not have been done). For example, medical professionals’ errors reportedly are the third leading cause of patient deaths in the US. In this session, we will explore the development of items that score both correct and incorrect decisions. We will see how the examination for directors serving on corporate boards use case-study items to help determine minimum competency for certification. Additionally, we will demonstrate the scoring algorithm and share how these items perform statistically.