We read this article and explored under what conditions self-assessment works best.
It should be noted that in some circumstances, students are not good judges of their own learning and therefore if the teacher chooses to use a self-assessment strategy in the class, they should monitor the students well.
Interestingly, this study shows that most people think they are better drivers than average - a statistic impossibility. A cognitive bias people have called the "illusory superiority" is a tendency to be overly optimistic in your own abilities or skills.
Rather than let students tell you whether or not they understand, do a quick whole-class check for understanding with mini whiteboards or use a hinge point question...
Self-assessments work best when students already know a lot about the subject and therefore can recognize their errors if asked to review. This strategy is good for non-novices to practice metacognitive skills.