Innovation in Playground Design

I recently came across an article in TIME about designing better playgrounds.
http://www.time.com/time/magazine/article/0,9171,2007398,00.html

David Rockwell designed playground equipment that consists of large foam blocks. Children can use them to build whatever they can imagine. In the article, children build cars, forts, etc.

We've been talking about how children's behavior contrasts with adults when it comes to imagination and design. Children have a lot of toys that encourage abstract representations, like Legos, dolls, blocks, and so forth. We wonder what happens between childhood and adulthood -- where does the creativity go? Children seem much less likely to fixate on the function of objects (seen in the real world, but also in research by German & Defeyter, 2000). Does fixation arise from additional knowledge, as suggested by the functional fixedness literature? Or is it the interaction with culture, expectations, etc.? Can innovation interventions help prevent fixation in design? We hope to find out through our research.