A major challenge for both educational researchers and practitioners is to understand why some people seem to learn more effectively than others and to design tools that can help less successful people improve their abilities to learn. In this chapter, we describe the most frequently documented metacognitive learning outcomes including: recall/memory; content learning/problem solving; and social interactions as knowledge acquisition. We then use each of these metacognitive learning outcomes to examine how today´s computer tools have or have not reached their fullest potential to support these learning outcomes and we suggest ways that computers tools can be designed to achieve these outcomes.