How Not To Sort By Average Rating
Average rating works fine if you always have a ton of ratings, but suppose item 1 has 2 positive ratings and 0 negative ratings. Suppose item 2 has 100 positive ratings and 1 negative rating. This algorithm puts item two (tons of positive ratings) below item one (very few positive ratings). WRONG.
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On correct formulas for ratings. Also, see another article for improved formula that works much better with smaller numbers of votes.
Link via person who “had to justify [his] expensive education”.
