Recommending Items

Finding a good critic to read is great, but what I really want is a movie recommendation right now. I could just look at the person who has tastes most similar to mine and look for a movie he likes that I haven’t seen yet, but that would be too permissive. Such an approach could accidentally turn up reviewers who haven’t reviewed some of the movies that I might like. It could also return a reviewer who strangely liked a movie that got bad reviews from all the other critics returned by topMatches.

To solve these issues, you need to score the items by producing a weighted score that ranks the critics. Take the votes of all the other critics and multiply how similar they are to me by the score they gave each movie. Table 2-2 shows how this process works.