**5. Conclusion**

This research was conducted to explore and articulate the knowledge-building process in interaction-based e-learning. For exploration of a knowledge-building process, an interactionbased e-learning program was developed and implemented at a college level course. Through‐ out the course, quantitative and qualitative data including the students' perceived knowledgebuilding process from questionnaires, online messages, interview data, and participatory observation journal were collected and analyzed. As results, an observable action model and a conceptual model of the knowledge-building process were derived, which students and experts verified. Cognitive achievement factors and satisfaction factors were also considered in the knowledge-building process model. Meaning and implication of each stage in the model were discussed.

The significance of this research is as follows: first of all, this study provides a conceptual framework for understanding a knowledge-building process in interaction-based e-learning such as online discussion learning. The model presented here was better articulated and elaborated based on empirical evidences, indicating social knowledge-building cycle is critically important in interaction-based learning. Historically learning has believed to occur within one's brain from an ultimately individual process. The results in this research provided a conceptual framework saying that there are two cycles and the social learning process as well as individual learning process is critical in interaction-based e-learning. Personal cognition and social activity might not be able to be separated artificially like the model in this research. Stahl [4] indicates by citing Hegel that it is the nature of a relationship of mutually constituting subjects: neither can exist without the other. But this kind of sequential visualization provides a more useful and clearer understanding of the knowledge-building process in interactionbased e-learning.

Second, this article provides a beginning to explain a mechanism of certain effectiveness of observable phenomena. For example, the report in [15] that vicarious interaction was a significant predictor of learning output could be correlated with the result that reading—as well as writing—messages on the discussion board was an achievement factor and a satisfac‐ tion factor. It is possible to explain that people learn sometimes by only reading even in interactive learning because people interpret social artifacts from socially shared understand‐ ing with an individual's own perspective to get to personal comprehension.

Third, several instructional design strategies such as externalization or group dynamics can be recommended. An interesting implication of this research is that if a student does not externalize either individually or socially, he/she cannot internalize the knowledge properly. This implies that instructors need to design *externalization* of a student's understanding as a requirement such as a 'Reflection paper' or 'Today's learning note', etc. Students who did not post messages actively during the class discussion could be required to wrap up the fierce discussions in order to experience group dynamics as well as externalization.

Besides, the knowledge-building process research in a resource-based self-learning environ‐ ment or their comparative study can be proposed for further study. Research of more cases in various learning contexts or considering more various learners' characteristics will also contribute to elaborate and generalize the model presented in this research and will enrich understanding of the theory and practice of interactive e-learning.
