Abstract
<jats:title>Abstract</jats:title> <jats:p>Inherent in the practice of assessment is the repeated administration of an instrument, either to a single individual across time or across multiple individuals. Reliability is the consistency of scores on a measure and is a feature of scores attributed to a measure, not the measure itself. In this chapter, the authors explore different methods of evaluating reliability of scores on a scale, provide insight in to the extent that a score represents an accurate and consistent measure of the construct among test takers, elucidate on the role of reliability in determining the usefulness of scores and assessment results, interpret reliability estimates, and apply reliability to the case conceptualization.</jats:p>