Self-regulated learners are able to set learning goals, find strategies that help them achieve those goals, and monitor their progress (Schraw, Crippen, and Hartley 2006). An important part of self-regulation is thinking about thinking, or metacognition. According to cognitive scientists (Donovan and Bransford 2005), metacognition involves self-monitoring and reflection on learning. Researchers have shown that metacognition can support student learning with understanding in many subjects. This month’s column describes how metacognition can support science learning and includes strategies that can be used to promote this critical skill.