Synthesizes literature on apprenticeship learning, the sociology of science, and K-12 science education to develop a set of characteristics for designing/evaluating participatory science learning experiences. Clarifies and illuminates the value of these characteristics for science educators by using them as evaluative criteria for characterizing the experiences of 24 middle school learners who embarked on a two-week camp with real scientists. (Contains 66 references.) (Author/ASK)