Years of experience, salary and time spent completing the exercise turned out to mean nothing.
Oddly, programmers from the same companies all performed at about the same level. Why?
The most important factor was the comforts afforded to them by their work environment: “… top performers overwhelmingly worked for companies that gave their workers the most privacy, personal space, control over their physical environments, and freedom from interruption.”
To find out, DeMarco and his colleague Timothy Lister devised a study called the Coding War Games. The purpose of the games was to identify the characteristics of the best and worst computer programmers; more than six hundred developers from ninety-two different companies participated. Each designed, coded, and tested a program, working in his normal office space during business hours. Each participant was also assigned a partner from the same company. The partners worked separately, however, without any communication, a feature of the games that turned out to be critical.
When the results came in, they revealed an enormous performance gap. The best outperformed the worst by a 10: 1 ratio. The top programmers were also about 2.5 times better than the median. When DeMarco and Lister tried to figure out what accounted for this astonishing range, the factors that you’d think would matter— such as years of experience, salary, even the time spent completing the work— had little correlation to outcome. Programmers with ten years’ experience did no better than those with two years. The half who performed above the median earned less than 10 percent more than the half below— even though they were almost twice as good. The programmers who turned in “zero-defect” work took slightly less, not more, time to complete the exercise than those who made mistakes.
It was a mystery with one intriguing clue: programmers from the same companies performed at more or less the same level, even though they hadn’t worked together. That’s because top performers overwhelmingly worked for companies that gave their workers the most privacy, personal space, control over their physical environments, and freedom from interruption. Sixty-two percent of the best performers said that their workspace was acceptably private, compared to only 19 percent of the worst performers; 76 percent of the worst performers but only 38 percent of the top performers said that people often interrupted them needlessly.
Join 25K+ readers. Get a free weekly update via email here.