Back to Resource Library Definitions of Play Gray, P. · 2013 ★ NIFPlay Rating: 6 Rating Scale 10 Rigorous play-specific science 6–9 General biological science 5 Sound play research (uncontrolled) 1–4 Less rigorous / indirect 0 Indirect but high value Peter Gray's scholarly review of how play has been defined across disciplines, proposing a synthesis definition centred on five characteristics including intrinsic motivation and positive affect. View Resource
