Recommendation systems produce a ranked list of items
on which a user might be interested, in the context of her
current choice of an item. Recommendation systems are
built for movies, books, communities, news, articles etc.
There are two main approaches to build a recommendation
system - collaborative filtering and content based [3]. Collaborative
filtering computes similarity between two users
based on their rating profile, and recommends items which
are highly rated by similar users. However, quality of collaborative
filtering suffers in case of sparse preference databases.
Content based system on the other hand does not use any
preference data and provides recommendation directly based
on similarity of items. Similarity is computed based on item
attributes using appropriate distance measures. We attempt
to hybridize collaborative filtering and content based recommendation
for circumventing the difficulties of these individual
approaches. Item similarity measure used in content
based recommendation is learned from a collaborative social
network of users.