The aim of this study is to design and develop an interaction model to perform the collaborative teaching process among pedagogical agents. A pedagogical agent has a role in a situation of the teaching process. However, the role is not fixed, but dynamically changed according to the learner's understanding. So, in this paper, we have analyzed the collaborative teaching process between one learner and two teachers for the subject of multiple fraction in elementary school, and extracted communication performatives and protocols for interaction required in this process as an interaction model. Moreover, we describe an example of a collaborative teaching process by using the extracted communication performatives and protocols.