If we have data, let’s look at data. If all we have are opinions, let’s go with mine.
—Jim Barksdale, former Netscape CEO
Recommendation systems, also known as recommendation engines, are a type of information system whose purpose is to suggest, or recommend, items or actions to users. The recommendations may consist of retail items (movies, books, etc.) or actions, such as following other users in a social network. Typically, the suggestions are a small subset selected from a large collection, according to criteria such as preferences previously expressed by users. Other possible criteria include age, gender, and location.
The most common strategies followed by recommendation systems are the following.
Collaborative filtering is perhaps the most popular of these strategies, due to its domain-free nature. Among collaborative filtering systems, one can further distinguish between neighborhood-based ...