\input zb-basic \input zb-ioport \iteman{io-port 05980200} \itemau{Hayashi, Yusuke; Isotani, Seiji; Bourdeau, Jacqueline; Mizoguchi, Riichiro} \itemti{An ontological model to blend didactic instruction and collaborative learning.} \itemso{Vivacqua, Adriana S. (ed.) et al., Collaboration and technology. 17th international conference, CRIWG 2011, Paraty, Brazil, October 2--7, 2011. Proceedings. Berlin: Springer (ISBN 978-3-642-23800-0/pbk). Lecture Notes in Computer Science 6969, 1-13 (2011).} \itemab Summary: Didactic learning that follows the ``traditional'' model of a teacher-student relationship is often considered completely different from collaborative learning. As a result, few studies have explored the potential to effectively connect these two forms of learning. Nevertheless, in practice, a well-thought-out linkage between these different approaches is essential to leverage and facilitate the learning process. Thus, in this paper, we propose an ontological model that captures the similarity between the two forms of learning, with a focus on participants' interactions. One of the benefits of this model is the creation of a flexible framework to describe learning independently of the approach used to learn. Second, it also enables us to describe the design rationale of learning scenarios and to organize theoretical knowledge for designing such scenarios in the same manner. To validate this model, we show its advantages with the examination in modeling theories for didactic and collaborative learning, and describe the development of an authoring tool for learning design that uses the model to facilitate the design of theory-based blended learning scenarios. \itemrv{~} \itemcc{} \itemut{} \itemli{doi:10.1007/978-3-642-23801-7\_1} \end