The researchers designed the study to achieve two goals: (1) determine the affect of peer collaboration on high school biology students' acquisition of concepts related to photosynthesis and (2) examine interactions in a collaborative peer group situation to determine how these interactions relate to the developpment of concepts associated with photosynthesis. Using quantitative and qualitative data analysis techniques, the researchers concluded that students working in peer collaborative groups developed more scientifically correct conceptions of photosynthesis than did students working alone. However, not all group-generated views were internalized by group members when assessed individually. Based on qualitative data, a functional relationship exists between prior knowledge and concept development. Two types of peer interaction, consonant and dissonant, were identified as enhancing concept development. When peer group roles are not assigned, roles fluctuate depending on group members' expertise or perceived expertise displaying a bidirectional zone of proximal development. This zone allows for enhanced concept development. Based on the above conclusions, the researchers recommend that (1) peer collaboration be used to help students overcome scientific misconceptions; (2) peer collaborative tasks be designed to engage students in consonant and dissonant interactions; and (3) cognitive group roles, as opposed to traditionl managerial cooperative group roles, be used.