Monday, October 30, 2006

Netflix and the bell curve

Average ratings
Originally uploaded by igrigorik.
igrigorik has posted several interesting graphs of Netflix users' ratings data on Flickr. This one shows that 3.8 is the average rating given to titles on Netflix.


  1. You might find it interesting that the average of user averages is lower at 3.6, and the average of movie averages is 3.2.

    The difference between 3.8 and 3.6 is explained by user's who have rated fewer movies tend to rate lower.

    The difference between 3.6 and 3.2is explained by user's deliberately selecting and rating movies that they prefer, and thusly rating poor movies less often, on average.

    Let that rattle around in the skullcase a bit. ;)

  2. No, I believe the data suggests that users who rate more movies rate lower, not the other way around.