This chapter discusses content-based recommendation systems, i.e.,
systems that recommend an item to a user based upon a description of the item
and a profile of the user’s interests. Content-based recommendation systems
may be used in a variety of domains ranging from recommending web pages,
news articles, restaurants, television programs, and items for sale. Although the
details of various systems differ, content-based recommendation systems share
in common a means for describing the items that may be recommended, a
means for creating a profile of the user that describes the types of items the user
likes, and a means of comparing items to the user profile to determine what to
recommend. The profile is often created and updated automatically in response
to feedback on the desirability of items that have been presented to the user.