Over the past decade, interpreter certification performance testing has gained momentum. Certification tests often involve high stakes, since they can play an important role in regulating access to professional practice and serve to provide a measure of professional competence for end users. The decision to award certification is based on inferences from candidates' test scores about their knowledge, skills and abilities, as well as their interpreting performance in a given target domain. To justify the appropriateness of score-based inferences and actions, test developers need to provide evidence that the test is valid and reliable through a process of test validation. However, there is little evidence that test qualities are systematicall...