Kruger & Dunning 1999 — low performers cannot self-assess skill (with caveats)

Claim: Kruger & Dunning (1999, JPSP) — bottom-quartile performers (actual 12th percentile) estimated themselves at the 62nd percentile; the unskilled lack the metacognition to recognize incompetence.

Honest concession: Serious statistical-artifact critiques exist. Krueger & Mueller 2002 and others argue the pattern is substantially a regression-to-the-mean + better-than-average effect artifact; Nuhfer et al. found little tendency toward inflated self-assessment for most people. The effect is real but its mechanism and magnitude are contested.

Source: Kruger & Dunning 1999, JPSP. Critiques: Krueger & Mueller 2002.

Confidence: Industry-consensus (effect direction); the strong metacognitive-deficit mechanism is contested.

Why this matters for Candid: We should not lean hard on a strong DK mechanism. The safer, better-established claim is simply that low performers cannot accurately self-assess skill — which is sufficient justification for the widget's "observe, do not rate" design.