Accurate self-monitoring of text comprehension is critical for effective self-regulated learning from texts. Unfortunately, it has been repeatedly shown that students’ monitoring of their text comprehension is often inaccurate, which can subsequently lead to inaccurate regulation and ineffective restudy decisions. Previous research provided evidence that completing causal diagrams at a delay after text reading (i.e., diagramming) can help to improve students’ monitoring of text comprehension. However, even after diagramming, there is still substantial room for improvement. The current studies therefore aimed to test whether providing feedback in the form of a correctly completed diagram (i.e., performance standard) would further increase students’ monitoring accuracy. In Study 1, 79 participants (aged 18–23) made judgements of learning under four conditions: I. No-Diagram (control), II. Standard-Only, III. Diagramming-Only, or IV. Diagramming + Standard. In each condition, students studied a text, made a judgement of learning before and after the experimental tasks, and completed a comprehension test at the end of each of the (overall six) trials. Results showed that only Diagramming + Standard improved monitoring accuracy and text comprehension. In Study 2, 20 undergraduate students (aged 18–23) completed the Diagramming + Standard condition while their eye movements were tracked and subsequently replayed for cued retrospective verbal reporting. The findings suggest that students used the standards to identify mistakes and improve their monitoring and text comprehension.