Research consistently demonstrates that well-designed outdoor play spaces offer considerable benefits to young children. Through free play and active exploration during playground time, children have opportunities to learn about, affect, and make meaning of their world, essential elements of learning (Wilson, 2007). The extent to which children master skills within the context of outdoor play depends largely on the environment they have access to. An alternative to the traditional, fixed playground design can be found in outdoor play environments that actively encourage children to explore and manipulate their environment using action-oriented, open-ended, or `loose parts' equipment. Research has revealed that children prefer and benefit from non-goal directed playground experiences that incorporate high levels of experimentation, innovation and complexity (Malone & Trantor, 2003). The methodology of the present study will be based on previous research conducted by Herwig, Shelly & Shim (2001). The goal of this study is to compare the quality, type of play and incidence of negative behaviors of two groups of children, younger and older preschoolers while playing on a `traditional' playground and while playing with a set of large, moveable foam pieces purposefully designed to promote open-ended free play. Forty preschool-age children will be observed for 10 minutes twice weekly, once playing in the `traditional' playground and once playing with the open-ended lose play material. Observations will be videotaped and coded using the Play Observation Scale-Revised (Rubin, 2001). Descriptive statistics will be used to analyze the quality and type of play, and the incidence of negative behaviors in each play settings. Significant differences between the two play settings across the two age groups will be explored using analysis of variance (ANOVA). Statistical analysis will be performed using SPSS statistics. Analyses will be deemed significant if the probability of a Type II error is p< .05.