The present study is an exploratory one which aims to investigate cognitive characteristics of face-to-face communication (FFC) and computer-mediated communication (CMC) in group discussion. FFC here refers to synchronous and spoken communication in which participants are copresent (located in the same place). CMC here refers to asynchronous and written communication in which participants are not copresent (separately located). Eighteen participants in two (FFC/CMC) conditions discussed the same topic, and the process of discussion was compared. Main results of the experiment are as follows : The characteristics of FFC are high redundancy, ill-structure, detailed personal episodes, weak linking with the main topic, and strong linking with others' ideas. On the other hand, the characteristics of CMC are low redundancy, well-structure, brief personal episodes, strong linking with the main topic, and weak linking with others' ideas. These characteristics were interpreted from three dimensions of communication ; synchrony, modality, and copresence. Finally, it was suggested that effective choice of communication media will vary depending on the purpose of group discussion (whether production of ideas or examination of ideas).