Children's early play with objects predicts their later communication skills, in both typically developing (TD) children and children with autism spectrum disorder (ASD). Many interventions for children with ASD are play-based, stimulating learning using objects the child enjoys. Not all children with ASD benefit equally from these interventions, perhaps in part because some children with ASD play in atypical ways. Thinking skills, such as control of attention, may affect object play. For example, a child's ability to shift attention makes it easier to stop playing with one toy in order to play with another. Playing with varied toys provides diverse opportunities for learning and interaction. In this study we will look at how object play, thinking skills and language development are related, in children with and without ASD. We will assess thinking and language abilities in 2- to 5-year-olds, including TD children and children with ASD. We will gather information about the range and level of children's play from videos of free play with an adult using a standard set of toys. This research is important because we need to know more about the behavioural and learning profiles of children with ASD as they relate to success in early intervention. Understanding more about these attributes may help improve therapy for young children with ASD. Given the rising rate of diagnosis of ASD, research in this field is pressing. These findings may contribute evidence relevant for the improvement of early interventions for young children with ASD. The expanding group of Canadian children diagnosed with ASD therefore stands to benefit from the results of this research.