This chapter illustrates why assessment is widely valued and considered a Best Practice by the training and development community. It presents an overview of the knowledge and skills communication consultants, coaches, teachers, and trainers (CCCTTs) should possess to conduct effective needs assessment and evaluation. The chapter seeks to familiarize novice CCCTTs with the language and basic how-to’s of assessments as well as provide veteran CCCTTs with new ways to refine their assessment approaches.