总结贝叶斯评级公式

Question

基于这个网址,我发现了贝叶斯评级,这很好地解释了评级模型,我想总结一下公式,使任何人实现SQL语句都更容易.如果我总结这样的公式,这会是正确的吗？

avg_num_votes  = Sum(votes)/Count(votes) * Count(votes)

avg_rating     = sum(votes)/count(votes)

this_num_votes = count(votes)

this_rating    = Positive_votes - Negative_votes

迦特

Answer 1

它看起来更像是这样的:

avg_num_votes  = Count(votes)/Count(items with at least 1 vote)
avg_rating     = Sum(votes)/Count(items with at least 1 vote)

this_num_votes = Count(votes for this item)
this_rating    = Sum(votes for this item)/Count(votes for this item)

如果你使用简单的+/-系统,Sum(votes) = Count(positive votes)(即将+视为1, - 为0)

另见:贝叶斯平均值.