Review: Dickey on Sackman (via Bowden)

Posted in programmer productivity, review at 4:17 pm by ducky

To reiterate, there’s a paper by Sackman et al from 1966 that people have seized upon to show a huge variation in programmer productivity, a paper by Dickey in 1981 that refuted Sackman pretty convincingly, and an article by Curtis in the same issue as Dickey’s. I didn’t talk much about the Dickey paper, but Tony Bowden has a good blog posting on the Dickey paper, where Dickey reports on a more reasonable interpretation of numbers from the Sackman’s data.

(Basically, Sackman compared the time it took to complete a task using a batch system against the time it took using a timeshare system. This was interesting in 1966 when they were trying to quantify the benefit of timeshare systems, but it’s not good to look at those numbers and say, “Ah, see, there is a huge variation in programmers!”)

Because I like making pretty histograms, here are the Sackman numbers via Dickey via Bowden — the way they ought to be interpreted. These show the time to complete for two tasks, the “Algebra” task and the “Maze” task.

The small sample size hurts, but (as in the Curtis data and the Ko data) I don’t see an order of magnitude difference in completion speed.

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  1. Best Webfoot Forward » VanDev talk summary said,

    February 6, 2008 at 9:28 pm

    […] 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. What I […]

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