Qualities of Expertise

Gaining expertise is difficult enough, but how can you tell if yourself (or someone else) has reached expert status? Unfortunately, multiple-choice tests are ineffective predictors since the benefit of expertise is being able to conjure up complex, situational-dependent solutions where there is no “correct” answer.

One of the simpler ideas is to see how long someone has been in an industry (say, 10+ years) and give them the benefit of the doubt. Surprisingly, for programmers at least, “programming experience gained in industry does not appear to have any effect whatsoever on quality and productivity.”1 Ironically, what does increase with experience is the confidence in your incorrect decisions.2

If you have the same one year of experience, ten years in a row, is that nine years of experience?3 Putting the time in is not necessarily effective. You need a strong feedback loop that allows you to hone your decision making and see what is effective,4 and an opportunity to vary and increase the difficulty and scope of your work.

To find expertise, we’ll need to look beyond the CV, using some generalized qualities across different domains.

Discrimination of subtle differences

The ability to make fine discriminations between similar, but not equivalent, cases is a defining skill of experts.

Empirical evaluation of the effects of experience on code quality and programmer productivity: an exploratory study

One of the most chill shows I watch is The Repair Shop. It’s a team of repair experts, taking worn down heirloom objects and returning them to their former glory. In one episode, art conservation expert Lucia Sclaisi is shown restoring a damaged painting. Where I see an old painting with a hole in it, Sclaisi sees:

  • the time period
  • the likely artist
  • the style
  • what has sullied the surface based on the color of the grime (she identified it as nicotine)
  • how highly finished it is and what finish is used (and thus how to best clean it)
  • and surely much more they didn’t show/I missed.

An expert can get information from clues that the novice didn’t even realize existed.

However, it’s not simply about knowing the information. If a quick Google search can tell us the answer, then it doesn’t require expertise. The big piece is knowing how to apply the information to make successful, situational-dependent decisions.


We all get lucky from time to time. Sometimes when the problem is a nail, we happen to have a hammer. Being able to consistently formulate a good solution to a variety of problems is the key here.

Situational-Dependent Solutions

I’ve mentioned “situational-dependent” several times now. What does that even mean?

As Andy Hunt emphasizes in Pragmatic Thinking & Learning: context is key.5 The same problem in a different context may require a different solution. Problems rarely have a one-size-fits-all solution. It requires expertise to correctly apply information within the right context.6

This means when encountering a new problem, an expert often asks important questions about the context. For example, the art restoration expert may ask where the painting has been stored, under what conditions, etc. I have a guess as to how some of these details could impact a painting, but I’m not sure how I could practically use that information. An expert does.

These details, which may seem unimportant to the novice, reveal nuances that can significantly inform the expert’s solution.

Assessing Expertise

Accurately assessing these qualities when hiring is easier said than done, and likely looks different across industries. However, the key qualities of expertise remain:

  • Ability to discriminate between subtle differences
  • Consistency
  • Situational-dependent solutions in the right context

If you are trying to assess expertise in an area that you don’t have much domain knowledge, Tyler Alterman has some great recommendations in their article, Why and how to assess expertise.

In many of my examples it’s easy to see the difference between a novice and an expert. Assessing someone proficient in a subject vs an expert can get tricky. In the end, if someone can consistently discriminate subtle differences in context-dependent situations to find the best solution, they’re well on their way to expertise.


  1. Oscar Dieste, Alejandrina M. Aranda, Fernando Uyaguari, Burak Turhan, Ayse Tosun, Davide Fucci, Markku Oivo & Natalia Juristo. Empirical evaluation of the effects of experience on code quality and programmer productivity: an exploratory study. Empirical Software Engineering. Feb 2017.
  2. James Shanteaua, David J. Weiss, Rickey P. Thomas, Julia C. Pounds. Performance-based assessment of expertise: How to decide if someone is an expert or not. European Journal of Operational Research. Apr 2000. p.254
  3. Andy Hunt. Pragmatic Thinking and Learning: Refactor Your Wetware. Sept 2008. p.15
  4. Tyler Alterman. Why and how to assess expertise. Effective Altruism Forum. Feb 2016.
  5. Andy Hunt. Pragmatic Thinking and Learning: Refactor Your Wetware. Sept 2008. p.35
  6. Iris Vessey. Expertise in Debugging Computer Programs: An Analysis of the Content of Verbal Protocols. IEEE Transactions on Systems, Man, and Cybernetics. Sept 1986.

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