Progress in understanding cognitive developmental change mechanisms requires methods that yield detailed data about particular changes. The microgenetic method is an approach that can yield such data. It involves (a) observations of individual children throughout the period of the change, (b) a high density of observations relative to the rate of change within that period, and (c) intensive trial-by-trial analyses intended to infer the processes that gave rise to the change. This approach can illuminate both qualitative and quantitative aspects of change, indicate the conditions under which
This paper discusses the development and visitor research of the George D. Widener Memorial Treehouse at the Philadelphia Zoo. The exhibit represents a non-traditional approach to education which involves the child as learner in the guise of an animal. This paper includes key findings from an evaluation study that aimed to achieve a systematic, working description of how visitors use "Treehouse"--what they are actually doing while they are there.