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Expertise and practice
Generated view: 15 sources whose Kunskapsbank note was filed under this theme, and the claims and candidates they link to.
Claims
C16 weakened
Deliberate practice, as it is usually measured, explains only a minority of the differences in how well people perform, in every domain studied. When only studies that use the strict original definition are kept, one reanalysis by the theory's author found about 29%, and estimated 61% after correcting for measurement error (Ericsson & Harwell 2019).
Serves: Q1
Ages: overgripande
Bounds: Share of individual differences in performance accounted for by accumulated deliberate practice, across domains; not whether practice improves performance within a person, and not specific practice schedules (C11). Evidence on file: Macnamara, Hambrick & Oswald 2014 (Psychological Science; meta-analysis; 26% games, 21% music, 18% sports, 4% education, under 1% professions); Ericsson, Krampe & Tesch-Römer 1993 (Psychological Review; the theory under test). The minority share holds for practice as usually measured and defined; for strict-definition studies corrected for unreliable measures, one reanalysis of 14 effects (games, music, sports, one education study, none from professions; reliabilities assumed by the authors) estimated 61% (Ericsson & Harwell 2019). Kill-condition test survived 2026-10-27: Macnamara, Moreau & Hambrick 2016 (Perspectives on Psychological Science 11(3), 333–350, DOI 10.1177/1745691616635591; full text stored; 52 independent samples, 63 effect sizes, N = 2,765): deliberate practice explained 18% of variance in sports performance (95% CI 12–25%); skill-level moderator significant, Q(2) = 7.04 — subelite 19% (r = .44), mixed 29% (r = .54), elite only 1% (r = .11, p = .50). Internally paced sports reached 41% (r = .64), still below half. Kill fails. Kill-condition test survived 2026-10-27 extra6: Platz, Kopiez, Lehmann & Wolf 2014 (Frontiers in Psychology 5:646, DOI 10.3389/fpsyg.2014.00646; OA full text stored; 13 studies, N = 788): task-specific practice ↔ musical achievement rc = 0.61 (95% CI [0.54, 0.67]); under the majority-of-variance kill, ~37% (upper CI ~45%) still below half. Authors caution against the r² reading; numbers still fail the kill.
Attack record: 4 attacks: 3 survived, 1 narrowed · Evidence links: 8 linked sources (6 supports, 1 limits, 1 challenges)
8 link(s) from sources in this view.
C18 weakened
Professionals who routinely work with AI assistance may perform worse at the same task when the AI is taken away than they did before they started using it; this is not established: one observational study found a drop (Budzyń et al. 2025), while a prospective study in the same endoscopists found none (Pedersen et al. 2026).
Serves: Q2
Ages: vuxen-livslangt
Bounds: Consistency bound added 2026-10-16 (week run): Pedersen et al. 2026 (Endoscopy; 13 endoscopists, 5,013 colonoscopies, before/during/after computer-aided detection) found no significant change in unaided polyp detection after the AI period. Unaided performance of trained professionals before versus after a period of routine AI assistance on the same task; not learners using AI during practice (C2), not people's beliefs about their own thinking (candidate K45). Evidence on file: Budzyń et al. 2025 (Lancet Gastroenterology & Hepatology; four Polish centres; adenoma detection in non-AI colonoscopy 28.4% before vs 22.4% after AI introduction, −6.0 points, 95% CI −10.5 to −1.6; observational); Parasuraman & Manzey 2010 (Human Factors; review of automation complacency and bias).
Attack record: 1 attack: 1 narrowed · Evidence links: 5 linked sources (2 supports, 2 limits, 1 challenges)
1 link(s) from sources in this view.
C30 killed
Music lessons have not been shown to make children reliably better at thinking skills or school subjects outside music: compared with an active control group the gain is at most small — about zero in the largest meta-analysis's main analysis (g = 0.056; Sala & Gobet 2020), about 0.2 standard deviations when the comparisons in which the control group trained the very skill being tested are dropped (pooled with passive-control studies; Bigand & Tillmann 2022), and 0.28 against active controls for instrumental programmes, with a confidence interval that includes zero (Román-Caballero et al. 2022).
Serves: Q1 (How do humans actually learn, and what helps them learn best?)
Ages: foralder-tidig-barndom, grundskola-lag
Bounds: Music training for children, non-music outcomes (verbal, non-verbal, memory, literacy, maths). Evidence on file: Sala & Gobet 2020 (Memory & Cognition 48, DOI 10.3758/s13421-020-01060-2; full text): 54 studies, 254 effects; active controls g = 0.056 (95% CI −0.069 to 0.182), −0.021 in sensitivity analysis; randomised studies with non-active controls g = 0.064; no difference between cognitive and academic outcomes. Challenge already on file: Bigand & Tillmann 2022 (Memory & Cognition, DOI 10.3758/s13421-021-01226-6; accepted manuscript): reanalysing the same data and dropping 21 comparisons where the control trained the very skill tested gave g = 0.208 — the first attack to weigh. Weakened 2026-10-31 (nightly attacks): Bigand & Tillmann 2022 re-read in the published version (Memory & Cognition 50(2), 339–347): the 21 removed comparisons were 18 phonological-training controls tested on phonology, 2 reading-intervention controls tested on reading and 1 visual-art control tested on visual form; the remaining 51 studies (233 effects) gave g = 0.208 (RVE, 95% CI 0.121 to 0.295; RE 0.195), pooled over active and passive controls, with type of control no longer a significant moderator (p = .193); without post-test-only studies g = 0.243. Román-Caballero, Vadillo, Trainor & Lupiáñez 2022 (Educational Research Review 35, 100436, DOI 10.1016/j.edurev.2022.100436; full text): instrumental programmes, 34 samples, 5,998 children, gΔ = 0.26 (0.12 to 0.39); randomised 0.26; active controls 0.28 (−0.06 to 0.61), randomised with active controls 0.23 (−0.13 to 0.58); one bias correction (RVE PET) cut the overall estimate to 0.01. Weakened 2026-11-05 (nightly attacks): Jamey, Foster, Hyde & Dalla Bella 2024 (Cognition 252, 105913, DOI 10.1016/j.cognition.2024.105913; full text, authors' copy): 22 longitudinal studies with controls, 1,734 children aged 3–11 (mean about 5 years 8 months); the 8 trials randomised at participant level with active non-music control training gave g = 0.60 (SE 0.11, 95% CI 0.39 to 0.82; I² = 0%; robust to rho, 0.55–0.60) on inhibition (flanker, go/no-go, Stroop or preschool versions); all 22 studies g = 0.31 (0.19 to 0.44); Egger p > .33. Limits: one inhibition measure per study, picked by the authors as the most suitable; post-tests right after short programmes; no blinding, every study rated 'moderate' quality; the authors note that playing music itself uses inhibition, so near and far transfer blur. Killed 2026-11-05 (Jonatan's decision): inhibitory control is a non-music cognitive result, and the 8 active-controlled randomised trials in Jamey et al. 2024 put it at g = 0.60 with an interval excluding zero, so the kill line below was met as written. The night run's rewrite of the claim and kill line (naming inhibitory control as an exception) was withdrawn; this is the wording that was attacked. The narrower idea that survives is now its own claim, C35.
Attack record: 2 attacks: 1 narrowed, 1 killed · Evidence links: 4 linked sources (1 supports, 2 limits, 1 challenges)
3 link(s) from sources in this view.
Music lessons do not reliably raise children's school results or broad thinking-skill measures more than active non-music activities do; the one shown exception is inhibitory control (g = 0.60; Jamey et al. 2024).
Serves: Q1 (How do humans actually learn, and what helps them learn best?)
Ages: foralder-tidig-barndom, grundskola-lag
Bounds: Children, music training compared with active non-music control activities; outcomes are school results (reading, maths, literacy, grades, standardised tests) and broad cognitive measures (IQ, general or composite reasoning, verbal or non-verbal ability, memory composites). Not about a single executive function picked per study, and not about music skills themselves. Created 2026-11-05 on Jonatan's decision after C30 was killed on its old kill line; every size below is carried over from C30's record. Sala & Gobet 2020 (Memory & Cognition 48, DOI 10.3758/s13421-020-01060-2; full text): 54 studies, 254 effects; active controls g = 0.056 (95% CI −0.069 to 0.182), −0.021 in sensitivity analysis; no difference between cognitive and academic outcomes. Bigand & Tillmann 2022 (Memory & Cognition 50(2), 339–347, DOI 10.3758/s13421-021-01226-6; published version): dropping 21 comparisons where the control trained the very skill tested left 51 studies (233 effects), g = 0.208 (95% CI 0.121 to 0.295), pooled over active and passive controls; without post-test-only studies 0.243 — the strongest challenge on file, but not an active-control-only estimate. Román-Caballero, Vadillo, Trainor & Lupiáñez 2022 (Educational Research Review 35, 100436, DOI 10.1016/j.edurev.2022.100436; full text): instrumental programmes, 34 samples, 5,998 children, gΔ = 0.26 (0.12 to 0.39) overall; active controls 0.28 (−0.06 to 0.61) and randomised with active controls 0.23 (−0.13 to 0.58), both pooled over all outcome types (Table 2). The paper gives no estimate for school results or broad cognitive measures against active controls alone: its literacy (0.20, 0.06 to 0.34), mathematics (0.23, −0.41 to 0.87) and intelligence (0.29, −0.00 to 0.58) figures pool active and passive controls (Table 3). Bias corrections: over randomised and non-randomised studies one correction (RVE PET) cut the estimate to 0.01; in randomised studies only, PET gave −0.04 (p = .881) and the selection model 0.15 (p = .207), while PEESE (0.18) and trim-and-fill (0.19 and 0.25) stayed near 0.2, and no test for publication bias was significant (Tables 4–5). Of the randomised studies with active controls, the authors cite the two with school-result outcomes (D'Souza & Wiseheart 2018; Haywood et al. 2015, 269 vs 279 pupils) as null results and two with intelligence outcomes (Schellenberg 2004; James et al. 2020) as positive (p. 2; Table 1). Outcomes measured at programme end only; no follow-up (corrected 2026-11-11). Exception: Jamey, Foster, Hyde & Dalla Bella 2024 (Cognition 252, 105913, DOI 10.1016/j.cognition.2024.105913; full text): 8 participant-randomised trials with active non-music controls, inhibition g = 0.60 (95% CI 0.39 to 0.82; I² = 0%); all 22 studies (1,734 children aged 3–11) g = 0.31; one measure per study picked by the authors, immediate post-tests, no blinding, and no academic or broad cognitive outcome.
Attack record: No attacks yet · Evidence links: 6 linked sources (2 supports, 2 limits, 2 challenges)
5 link(s) from sources in this view.
Candidates (not approved)
- K40: Studying worked examples helps novices more than solving the same problems themselves, but the advantage shrinks or reverses as learners gain expertise. (1 link(s))
Sources