This study conducted at a suburban community college tested a method of conceptual change in which treatment students worked in small cooperative groups on tasks aimed at eliciting their misconceptions so that they could then be discussed in contrast to the scientific conceptions that had been taught in direct instruction. Categorizations of student understanding of the target concepts of the laws of conservation of matter and energy and aspects of the particulate nature of gases, liquids, and solids were ascertained by pre- and posttesting. Audiotapes of student verbal interaction in the small groups provided quantitative and qualitative data concerning student engagement in behaviors suggestive of the conditions posited to be part of the conceptual change process (Posner, Strike, Hewson & Gertzog, 1982). Chi-square analysis of posttests indicated that students in treatment groups had significantly lower (p < 0.05) proportion of misconceptions than control students on four of the five target concepts. Students who exhibited no change in concept state had a higher frequency of verbal behaviors suggestive of “impeding” conceptual change when compared to students who did change. Three factors emerged from qualitative analysis of group interaction that appeared to influence learning: (a) many students had flawed understanding of concepts that supported the target concepts; (b) student views towards learning science affected their engagement in assigned tasks, (c) “good” and “poor” group leaders had a strong influence on group success.