rating-score

You are a web programmer. You have users. Your users rate stuff on your site. You want to put the highest-rated stuff at the top and lowest-rated at the bottom. You need some sort of “score” to sort by.

– Evan Miller, “How Not To Sort By Average Rating”

A better way to calculate ranking score to sort things on the web based on user upvotes or “stars”, using lower bound of Wilson score confidence interval for a Bernoulli parameter.

API

Table of Contents

• averageToScore
  • Parameters
• starsToScore
  • Parameters
• upvotesToScore
  • Parameters

averageToScore

Calculates the score from the average of all reviews.

This function is curried.

Parameters

• confidence Number
• averageRating Number Average review score.
• maxRating Number Maximum review score.
• totalReviews Number Total number of reviews.

Returns Number Calculated score.

starsToScore

Calculates the score from a list of review counts.

This function is curried.

Parameters

• confidence Number
• starsList Number List of review counts.

Returns Number Calculated score.

upvotesToScore

Calculates the score from the number of upvotes and downvotes.

This function is curried.

Parameters

• confidence Number
• upvotes Number Number of positive reviews.
• downvotes Number Number of negative reviews.

Returns Number Calculated score.