Abstract
Psychometrics, or psychometry, is defined as the science of psychological assessment. It involves inspection of psychological instruments for their reliability and validity, the two core dimensions of psychometric evaluation. These psychometric properties indicate the extent to which an instrument approximates the true measurement of a construct of interest. This chapter examines the core dimensions of psychometric evaluation, reliability and validity, as they relate to child behavioral assessment. It discusses the strategies used to evaluate these psychometric properties, with examples from common child behavioral assessment instruments. The chapter also addresses the research and clinical issues related to test–retest reliability, interrater reliability, alternate-form reliability, internal consistency, and internal structure. Furthermore, it sheds light on the issues related to face validity, content validity, and criterion validity as well as the more specific types of validity within the general category of criterion validity (that is, discriminative, concurrent, and predictive validity). The chapter concludes with a discussion on research and clinical implications for psychometric issues in child behavioral assessment.