The ToP is an observational assessment administered by an
unobtrusive rater during a 15-min sample of free play in a
familiar environment with familiar peers. Playfulness is rated
on 30 items, using a 4-point (0–3) scale that reflects extent,
intensity, or skill. The ToP has been shown in numerous
studies to have adequate evidence for reliability and validity
(e.g., Bundy et al., 2001).