Several computer-based learning support systems and methods help learners to master metacognitive activity. Which systems and methods are designed to eliminate which difficulties associated with the learning of metacognitive activity through its clear specification? We adopt a method in our research that supports learning by eliminating salient difficulties. We believe that it is possible to eliminate or decrease them through appropriate design only after specifying those difficulties associated with learning. In this study, we analyze difficulties in performing cognitive activity, distinguish factors of difficulty from other factors, and construct our framework, which represents difficulties in performing metacognitive activity. Finally, we organize existing support systems and methods based on that framework.