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Schooling Microsoft On Random Browser Selection
Rob Weir got wind that a Slovakian tech site had been discussing the non-randomness of Microsoft's intended-to-be-random browser choice screen, which went into effect on European Windows 7 systems last week. He did some testing and found that indeed the order in which the five browser choices appear on the selection screen is far from random — though probably not intentionally slanted. He then proceeds to give Microsoft a lesson in random-shuffle algorithms. "This computational problem has been known since the earliest days of computing. There are 5 well-known approaches: 3 good solutions, 1 acceptable solution that is slower than necessary and 1 bad approach that doesn’t really work. Microsoft appears to have picked the bad approach. But I do not believe there is some nefarious intent to this bug. It is more in the nature of a 'naive algorithm,' like the bubble sort, that inexperienced programmers inevitably will fall upon when solving a given problem. I bet if we gave this same problem to 100 freshmen computer science majors, at least 1 of them would make the same mistake. But with education and experience, one learns about these things. And one of the things one learns early on is to reach for Knuth. ... The lesson here is that getting randomness on a computer cannot be left to chance. You cannot just throw Math.random() at a problem and stir the pot and expect good results."
A Google search on:
gives exactly the bogus answer that Microsoft used in the top hit.
Unfortunately for Microsoft, a bing search gives the same top hit.
I don't know what you consider "99.99% random", but the difference between 20% (probability of IE turning up last in a real random shuffle) and ca. 50% (probability of IE showing up last in the implemented "random shuffle") is certainly significant enough that you can't call it 99.99% random." You might argue that it is "random enough for this," but that's of course a matter of opinion, and therefore debatable (there's no objective definition of "random enough").
The Tao of math: The numbers you can count are not the real numbers.
Both the article and the summary mixes up the concepts. Randomness and bias are related but different things. Think of a biased coin loaded in favor of heads - the heads may appear twice as often as the tails, but the distribution is still random. Here too, contrary to the summary's claim of "far from random", the results are random, just biased, and biased against IE, if I may add, which is an important fact the summary omitted.
You know, your post just made me realize that Microsoft has made a good entry for perhaps next year's Underhanded C Contest: write some innocent-looking code that is supposed to randomize a selection, but fails to do so fairly and favors certain selections over others.