Early Findings in the Development of Expertise*

Adriaan DeGroot (1914-2006)

Adriaan DeGroot and later Simon and Chase developed what's considered the original theory of human expertise.  DeGroot, a Dutch chess master turned psychologist, is known for his studies of chess and memory.  These early theorists emphasized the importance of extended experience in attaining expert levels of achievement.  

Subsequently, Anders Ericsson, with the advantage of updated information, better research access, and modernized tools, put a hard qualification on DeGroot's finding.  Ericsson found that only narrow forms of deliberate practice would yield expertise. Since DeGroot's time, we've come to see that the raw number of years of experience is a poor predictor of objective performance.  There's ample evidence from a wide range of fields to show this.  

In fact, it's worse.  In some cases, such as in applied medical positions, there can be an inverse relationship.  Additional years of experience after a certain point correlates with lower levels of performance in certain tasks. 

Both of these dismal findings are easily explained.  Someone once quipped that you can have 10 years of experience or 2 years of experience 5 times. That quip addresses the first finding, that performance doesn't steadily rise along with time on the job.  Obviously, not all experience is progressive.  

The second finding, where performance may actually deteriorate over time, surely (imo) comes from the time-gap between formal training and job application.  Education is front-loaded.  You spend years in school, doing nothing but learning and studying. Then, once on the job, you spend much of the initial period engaged in learning activities .  Orientation, job-skills training, apprenticeships,  certifications.  By comparison, you spend much less time in such training after the initial year or so.  Naturally, the further out you are from this formal learning, the more you forget.  And, once underway on the job, you learn less from reading or formal sources (proven, verified theory); you learn more from others (who may not follow the theory, or even do things correctly!); and you start slacking on the fundamentals and take more short-cuts (good and bad). 

So sure, experience is not a guaranteed path to expertise. 

Yet, DeGroot is right in one important sense: quantity matters.  While it's true that not all of those with lots of experience become experts, all experts have lots of experience.  In that there are no exceptions.  One way or other you need the trials. 

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* Development of Professional Expertise, Toward Measurement of Expert Performance and Design of Optimal Learning Environment🇱🇱

Edited  by K. Anders Ericsson