Debate exists about the defining characteristics of play, yet there have been few empirical studies to assess the reliability of existing categorizations. This preliminary study aimed to identify and assess the reliability of criteria generated by participants themselves to categorize
children's play. Twelve participants (6F/6M), who were experienced in observing children's play, were shown eight video excerpts of children's play and asked questions to elicit (a) the criteria they used to categorize play and (b) the features of each play episode that
were salient to the participants. Results showed that participants categorized play according to a mixture of Behavioral (Positive Affect; Nonliterality; Unrestrained/Unrestricted); Motivational (Practice; Communication and Cooperation) and Contextual (Presence of
toys and props) criteria. These criteria were mostly comparable with existing criteria used to categorize play. Results are discussed in terms of the multidimensional nature of children's play and its characteristic and reliably identifiable features.