Review: DeMarco and Lister's Programmer performance and the effects of the workplace

Posted in programmer productivity, review at 5:12 pm by ducky

I got started on looking at productivity variations again and just couldn’t stop. I found Programmer performance and the effects of the workplace by DeMarco and Lister (yes, the authors of Peopleware). The paper is well worth a read.

In their study, they had 83 pairs of professional programmers work all on the same well-specified programming problem using their normal language tools in their normal office environment. Each pair was two people from the same company, but they were not supposed to work together.

  • They found a strong correlation between the two halves of a company pair, which may be in part fromcorrelation of productivity across a company
    • a pretty stunning correlation between the office environment and productivity
    • (or perhaps due to different companies having radically different tools/libraries/languages/training/procedures, which they didn’t discuss)
  • The average time-to-complete was about twice the fastest time-to-complete.
  • Cobol programmers as a group took much longer to finish than the other programmers. (Insert your favorite Cobol joke here.)

productivity differences

Over and over, I keep seeing that the median time to complete a single task is on the order of 2x to 4x times the fastest, not 100x. This study seems to imply that a great deal of that difference is due not to the individual’s inherent capabilities, but rather the environment where they work.


  1. Jokes Blog Search » Blog Archive » DeMarco and Lister said,

    February 16, 2007 at 5:49 pm

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    February 17, 2007 at 3:26 pm

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  3. People Over Process » Blog Archive » Gaming Your Context, or, Methodology by Constraints said,

    February 19, 2007 at 10:19 am

    […] In response to one of Anne’s recent bookmarks — every pro-office (a room, not Microsoft) coders favorite study — Christopher Mahan leave a nice reply about the Super Code Monkey: No, the 10,000 times more productive developer is the one who has the experience, the guts, the curiosity, the hard-headedness and the stick-to-itiveness to go forth and take over entirely unchartered territories.This developer has carefully selected his tools, mastered his environment, from the idiosyncrasies of his OS, to writing lexical parsers for his language of choice in his language of choice, to tackling problems that to management seem like utter wastes of time but that could resolve a obscure bug on an obscure product, a bug so obscure it has only occurred three times in the History of Computing. Yet, it is in this utter dedication to that task that the brain trains itself to be devastatingly thorough, to anticipate the impact of every single byte on the expected result, to watch in his mind’s eye avenues of opportunities and dead-end boulevards unfold ever-forward, beyond release date, beyond maintenance and product end-of-life, all the way to its ultimate impact on the common psyche of programmers, as tricks of the trade and techniques passed from generation to generation. […]

  4. Best Webfoot Forward » VanDev talk summary said,

    February 6, 2008 at 9:28 pm

    […] some people who have measured coding speed, however. I have reported previously on experiments by Demarco and Lister, Dickey, Sachman, Curtis, and Ko which measure the time for a number of programmers to do a task. […]