Accurate knowledge monitoring is critical to the learning process, as it allows one to regulate studying and test preparation. Thus, a number of investigations have attempted to improve metacognition in the classroom, with the ultimate goal of improving student exam performance. However, such interventions have had inconsistent success using varying paradigms. We compared the effectiveness of five interventions aimed at improving prediction accuracy in a laboratory environment: review, salient feedback, motivation warning lecture, incentives, and reflection. Only the salient feedback and the motivation warning lecture interventions significantly improved participants' prediction accuracy from test 1 to test 2. Review, incentives, and reflection did not improve predictive or postdictive calibration. Well-timed salient feedback and a lecture warning students not to be biased by desired grades were effective methods of improving calibration accuracy. Results offer effective interventions to improve metacognition that could be used in a classroom setting.