This paper focuses on the importance of play for a child's physical, emotional, cognitive, and social development. Three major purposes of the report are: (1) to persuade those concerned with the education of young children that play is an essential activity for children's well-being and should be facilitated at home and in the classroom, (2) to shed light on the special value of sociodramatic and symbolic play, and (3) to explore possible ways to observe play and to discuss how these observations can be used by parents and teachers. The importance of play is reviewed from the perspective of many different theories of development. A general normative sequence of development of play behavior is presented for infancy through age five. Daydreaming and sociodramatic play are discussed in terms of the role of the adult, recent research findings, environmental and equipment influences, and sequence of development and significance of imaginative ability. Finally, common observation methods are reviewed, with emphasis on the need for parents and teachers to refine and use observational skills. (DP)