Studying infant and toddler play.

The play of infants and toddlers is a rich and flexible research modality. Play assessment can be an outcome measure of cognition or social ability, or it can be measured in conjunction with related constructs such as language to give a broad view of early development. Play can also be an effective intervention in studies of cognition, language, motor, or social development. This article offers strategies for the researcher who is interested in infant and toddler play. Emphasis is placed on environmental variables that the researcher manipulates to optimize the child's performance. Play measures are briefly addressed.