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  • Dr Paul Penn

Metacognitive errors: the biggest barrier to developing effective approaches to studying.

Updated: Nov 29, 2019

“The greatest obstacle to discovery is not ignorance – it is the illusion of knowledge.” Daniel Boorstin.

Your efforts to learn are tied to how accurately you can monitor and evaluate your levels of knowledge and understanding (i.e. your metacognitive ability). There is little incentive to invest time in studying something if you think you already know it. Equally, you're probably not going to be inclined to work on developing a skill if you're convinced that you're already sufficiently proficient. This would be all well and good if our perception of our competence reliably reflected our objective levels of ability. Unfortunately, research indicates that our metacognition is subject to an array of errors that give us an inflated impression of our levels of knowledge and skill.

A particularly cruel example of a metacognitive error was originally demonstrated by Kruger and Dunning (1999). They conducted a series of experiments in which undergraduate Psychology students were asked to participate in a series of assessments of humour, grammar and logic. Each assessment involved asking the participants to rate their anticipated level of performance relative to their peers. The results indicated that the students who had scored in the bottom quartile (25%) of the group had rated their performance in the top third of the sample. However, their actual position was in the lower end of the bottom third of the sample. It transpired that the more objectively incompetent an individual was, the more they were unaware of it (as evidenced by the size of the discrepancy between their perceived and actual ability). This finding was dubbed the ‘Dunning Kruger Effect’ and has become a robust finding in Psychology that persists whether competence judgements are made relative to peers or in absolute terms, over a range of laboratory and real world tasks and even when accuracy is incentivised (Ehrlinger, Johnson, Banner, Dunning and Kruger, 2008).

Figure 1: Illustration of the Dunning Kruger effect.

The Dunning Kruger effect has been attributed to the fact that it’s the same skills that generate competence that are necessary to evaluate the level of competence achieved. Kruger and Dunning (1999) tested this in their experiment by asking participants to assess the competence of others, which resulted in the least competent also being the least accurate in their evaluation of the competence of others. Similarly, recent research (Pennycook, Koehler and Fugelsang, 2017) found the Dunning Kruger effect in a test of cognitive reflection ability whereby the poorest performing students overestimated their performance by a factor of 3, but also self reported a disposition towards analytical thinking completely at odds with their objective ability.

The Dunning Kruger effect means that the primary challenge for efforts to promote effective study practices is how to address the misalignment of perceived and actual ability, such that the individuals (especially those in the greatest need of some guidance) recognise the need to engage with the material in the first instance. Simply confronting them with the discrepancy between their perceived and actual performance per se via feedback is inadequate (e.g. Simons, 2013). However immediately accompanying such feedback with training for the very skills that the student currently lacks may, paradoxically, be the solution.

You can find more information on metacognitive errors (and how to overcome them) in chapter one of my new book 'The Psychology of Effective Studying: How to Succeed in Your Degree' available direct from the publishers here (this link also features an order inspection copy facility for tutors/librarians). The book can also be purchased from or


Dunning, D. (2013). The problem of recognizing one’s own incompetence: Implications for self-assessment and development in the workplace. Judgment and decision making at work, 37

Ehrlinger, J., Johnson, K., Banner, M., Dunning, D., & Kruger, J. (2008). Why the unskilled are unaware: Further explorations of (absent) self-insight among the incompetent. Organizational behavior and human decision processes, 105 (1), 98-121.

Pennycook, G., Ross, R. M., Koehler, D. J., & Fugelsang, J. A. (2017). Dunning–Kruger effects in reasoning: Theoretical implications of the failure to recognize incompetence. Psychonomic Bulletin & Review, 1-11.

Simons, D. J. (2013). Unskilled and optimistic: Overconfident predictions despite calibrated knowledge of relative skill. Psychonomic bulletin & review, 20 (3), 601-607.

PS. On the lighter side, here’s a video John Cleese giving his account of the Dunning Kruger effect. Maybe I should have saved myself the effort of composing the text for this blog and just posted this!

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