One not-so crude method of establishing the similarity between texts was presented to me in String::Trigram, which was used by its author for just that, determining how similar two webpages are. The method is still crude as it doesn't discriminate between HTML and "real" text, but the author claimed it worked well enough for him because minor differences like timestamps etc. made only a small change in the resulting number.

In reply to Re: Quantitative Change instead of Boolean by Corion
in thread Quantitative Change instead of Boolean by titivillus

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