21 lines
801 B
Plaintext
21 lines
801 B
Plaintext
Suppose you flip a coin 100 times, and it turns up heads 70 times. Is
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the coin fair?
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Suppose you roll a die 100 times, and it shows 30 sixes. Is the die
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loaded?
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In statistics, the chi-square test calculates "how random" a series of
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numbers is. But it doesn't simply say "yes" or "no". Instead, it gives
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you a confidence interval, which sets upper and lower bounds on the
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likelihood that the variation in your data is due to chance. See the
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examples below.
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There's just one function in this module: chisquare(). Instead of
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returning the bounds on the confidence interval in a tidy little
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two-element array, it returns an English string. This was a deliberate
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design choice---many people misinterpret chi-square results, and the
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string helps clarify the meaning.
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-Anton
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<tobez@FreeBSD.org>
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