A simpler solution: Weighted score = (positive + alpha) / (total + beta) In which alpha and beta are the mean number of positive and total votes, respectively

A simpler solution: Weighted score = (positive + alpha) / (total + beta) In which alpha and beta are the mean number of positive and total votes, respectively. You may wish to estimate optimal values of alpha and beta subject to some definition of optimal, but I find the mean tends to work well enough for most situations.