This study investigated whether providing students with the choice of chat versus threaded discussion boards for online discourse is an effective instructional strategy in terms of student learning and satisfaction. The sample was teacher education students enrolled in face-to-face (FTF) and online sections of one undergraduate foundations course. Both sections required participation in online text-based discussion. Comparison groups included course format (FTF vs. online), discussion format (chat vs. discussion board) and discussion format option (choice vs. no choice). Results reveal that students' choice of discussion format was influenced by the trait of academic introversion-extraversion but not by the instructional environment (FTF or online) in which they enrolled. In addition, providing the choice of discussion format to students enhanced course satisfaction and, while some differences were found in cognitive achievement, the results were weak. (Contains 4 figures and 6 tables.)