Page "Recommender system" Paragraph 7

* Pandora uses the properties of a song or artist ( a subset of the 400 attributes provided by the Music Genome Project ) in order to seed a " station " that plays music with similar properties.

User feedback is used to refine the station's results, deemphasizing certain attributes when a user " dislikes " a particular song and emphasizing other attributes when a user " likes " a song.

This is an example of a content-based approach.