Expanding on the extant body of research on content validity, this study applied the tenets of content validity research to the development of an expository book reading intervention focused on science for preschool students with language impairment. This example case explains how, guided by content validity research in healthcare interventions, collaboration with an expert panel was systematically approached in the development of an educational intervention. Specifics as to how feedback was gathered and analyzed are discussed. Of practical importance for practitioners and researchers, this study provides a detailed description of how the knowledge and experience of a panel of experts was captured, analyzed, and incorporated into the development process of an educational intervention to validate its application.