Deliberate Practice and Proposed Limits on the Effects of Practice on the Acquisition of Expert Performance: Why the Original Definition Matters and Recommendations for Future Research.
Level 5 - mechanism / opinion, no new human data
Level assigned by non-clinical design analogy: narrative critique and methodological reanalysis of a prior meta-analysis.
PubMed 31708836 · doi:10.3389/fpsyg.2019.02396
What was done
The authors reviewed the criteria defining deliberate practice versus general structured practice, critiquing the methodology of a previous meta-analysis by Macnamara et al. (2014). They established three specific criteria for reproducible performance and purposeful/deliberate practice, excluded studies from the Macnamara dataset that failed to meet these criteria, and reanalyzed the remaining effect sizes.
What was found
Macnamara et al. (2014) originally reported that practice accounted for 14% of the variance in performance. Reanalysis of the subset of studies meeting the authors' deliberate practice criteria showed that accumulated practice duration accounted for 29% of performance variance, and 61% after correcting for attenuation. Genetic factors were reported to account for small amounts of variance, with exceptions for body size and height.
Why it matters
This critique argues that using overly broad definitions of practice underestimates the true impact of deliberate practice on achieving expert performance.
Limits
The abstract does not state the number of studies or total participant sample size included in the final reanalysis. Reanalyzing secondary data with post-hoc inclusion criteria introduces selection risk. Furthermore, practice duration relies on developmental estimates rather than real-time objective tracking and fails to capture qualitative dimensions such as concentration and problem-solving.
Cited by
- supports In Anders Ericsson's research on expert violinists, the musicians typically practiced for about two sessions of 60 to 90 minutes per day.
- supports Elite musicians practice for three to four focused hours per day rather than extensive hours like 11 hours a day.
- supports The study by Anders Ericsson found that 10,000 hours was the average practice time accumulated by expert violinists by age 20, rather than an absolute threshold for achieving expertise.