Abstract: Collaboration centered in peer conversation is the most frequently used online learning design. However, studies question this conventional wisdom, suggesting peer conversations are often only exchanges of personal experiences not well-supported reasoning that sustains interest and engagement. Teacher-learners’ perceptions of their conversations in an online course using a peer collaboration (PC) model and in an online course using an expert mentor- learner (EML) model were examined (one group - two treatment research design). No significant differences were found in perceptions of the content of conversation between the two models, although seeking and providing clarification favored the EML model and organizing work and producing products favored the PC model. There were significant differences in teacher-learners’ perceptions of the attributes of their conversations. They attributed helpful and inspiring more positively to the EML model and the attributes of frustrating and inconsistent more positively to the PC model.