We investigated the effect of working memory capacity and mental effort on the ability to monitor the accuracy of text comprehension. Participants completed the operation span test to measure working memory capacity (WMC) and read five scientific expository texts. In low-effort condition, participants read intact texts, whereas in high-effort condition, participants read texts that had some letters deleted. After reading, participants assigned comprehension rating to each text and then completed a comprehension test. The result showed a significant interaction between WMC and mental effort. Increased effort improved the accuracy of low-WMC readers but decreased the accuracy of high-WMC readers. Further, in tow-effort condition, high-WMC readers monitored their comprehension more accurately than did low-WMC readers. In high-effort condition, low-WMC readers monitored their comprehension more accurately than did high-WMC readers. Our findings showed that both WMC and mental effort affected the ability of participants to monitor their accuracy. These findings are discussed.

Key words: Monitoring accuracy, Working memory, Mental effort