Abstract: This study investigated how students and adults use probability-generating devices (colored bears, dice, spinners, colored disks) to model different contextual tasks. Seven Midwestern USA students in grades 2 through post-secondary were interviewed to assess their probabilistic reasoning as they identified models for one- dimensional and two-dimensional tasks. The results showed that all but the second grade student were able ti use correspondence between sample space elements in the context and in the generator to identify and justify their models. Even prior to instruction students exhibited intuitive notions of correspondence that played a major role in enabling them to model. Student who demonstrated stronger links between modeling and theoretical probability were also able to model two- dimensional contexts and make more connections among equivalent generators. A key implication of this study is that students’ intuitive knowledge of correspondence is a powerful concept on which to build instruction in experimental probability.