This chapter will discuss the methods used by researchers in various disciplines to assess play development and learning in groups of children, the issues and practices related to the use of play-based assessment with individual children and the characteristics of both early and recent play-based assessment techniques for understanding three aspects of individual child development: (a) assessment of a child's play development itself; (b) Assessment of a child's level of cognitive, language, social, and other abilities exhibited during play; and (c) assessment of abilities/disabilities in play for which therapeutic interventions may be needed. It will provide selected examples of play-based assessment instruments and discuss their characteristics and uses. (author abstract)