Human-scored performance items offer measurement options beyond those of standard selected-response item types, but require careful planning. This session will identify the most common mistakes made during the development and administration of performance items, as well as real-world strategies for how these mistakes can be avoided. The session will also feature a case study and an interactive exercise. The session will be structured as follows: -Each presenter will provide personal background information, then the topic will introduced to the attendees. (15 minutes) -The presenters will survey the top five mistakes in performance testing. Scott Russell and EW Looney will provide conceptual information behind each mistake, while Jack Terry will provide real-world examples for dealing with these mistakes. (45 minutes) -Presenters will engage in a question and answer period. (10–15 minutes) -An interactive exercise will be conducted in which attendees will be given the opportunity to evaluate and discuss the practices of a fictitious testing organization.