Transactive Discourse During Assessment Conversations on Science Learning by Homer A. Russell III It has been argued that development of science knowledge is the result of social interaction and adoption of shared understandings between teachers and students. A part of understanding that process is determining how student reasoning develops in groups. Transactive discussion is a form of negotiation between group members as they interpret the meaning of their logical statements about a topic. More importantly, it is a form of discourse that often leads to cognitive change as a result of the interaction between group participants as they wrestle with their different perspectives in order to achieve a common understanding. The research reported here was a correlational study designed to investigate the relationship between the various forms of transactive discussion and learning outcome performance seen in an investigation involving 24 students in a middle-SES high school located in southwest Atlanta, Georgia. Pretest and posttest measures of genetics reasoning, as well as curriculum content test data, were used in this study. Group discussion was captured on videotape and analyzed to determine whether transactional discussion was present and whether or not it had an effect on learning outcome measures. Results of this study showed that participant use of transactive discussion played a role in development of reasoning abilities in the area of genetics. It is suggested that teachers should monitor classroom discourse for the presence of transactive discussion as such discourse plays a role in fostering performance outcomes.