We examined how massive open online courses (MOOC) learners' motivational factors, self-efficacy, and task-value related to their course progress and achievement, as informed by learners' initial course completion intention. In three individual MOOCs, learners completed a pre-course survey to report their levels of task-value and self-efficacy and to indicate their intention to complete each course topic. Using clustering techniques, we identified two distinct groups of learners in the three MOOCs based on self-efficacy and task-value variables: higher-motivation group and lower-motivation group. The higher-motivation group achieved significantly higher grades in two of the MOOCs, and also adhered to their initial completion intention significantly more so than the lower-motivation group. We posit that MOOC completion research should consider learners' topic-level interest as one success criterion. Further research can clarify perceived task-value in relation to learners' existing knowledge, their learning goals, and learning outcomes related to the MOOC participation.