Environmental design research and participation can enable groups with different environmental values to negotiate critical design decisions. This article presents findings and techniques from two open space projects—one a neighbourhood playground, the other an elementary schoolyard—found to be useful in clarifying differences in open space values and preferences. Specific differences between child and adult views of these places are reviewed. How participation and research was utilized to help resolve basic open space differences is discussed. The article concludes with a brief review of future issues facing research and design participation.