MUSICFX [22] chooses a radio station for background music in a fitness centre, to suit a group of people working out at a given time. This is similar to the Ambient Intelligence scenario discussed above.
• POLYLENS [25] is a group recommender extension of MOVIELENS. MOVIELENS recommends movies based on an individual’s taste as inferred from ratings and social filtering. POLYLENS allows users to create groups and ask for group recommendations.