Play is children's active involvement with the environment and the things in it. It is apparently enjoyable, voluntary, self-initiated, often social and a natural product of the processes of physical, social and cognitive growth. Play is also the context in which parents interact often and meaningfully with their children. But what do parents or families know, and need to know, about how to provision and facilitate children's activity and learning? Children's play is the lens through which parents can look to their child as a source of guidance concerning what to do with, for, and in support of the child as a rapidly developing organism. Educational, psychological and developmental theories have their place in completing anyone's understanding of learning, but parent child interaction is fundamentally nurturant and not instructional. Perhaps children's play activities with material things could be thought of as work occupations similar to adult work. Five patterns of play occupations can be identified in adults' recollections of play: the child as explorer, constructor, communicator, thespian, and athlete. With appropriate materials, the growth and development of children in these play occupations can be encouraged. The model of parent child interaction is very much an I-Thou-It model in which parents provide encouragement and suggestions for alternative possibilities with appropriate materials. (In conclusion, qualities of materials that support young children's play are listed.) (RH)