A method for determining user interests is provided, the method comprising: storing data items relating to usage patterns of the user, wherein the data items include an interest portion and a context portion; grouping the data items into context groups, each context group having data items with related context portions; for each context group, determining if the number of data items in the context group is greater than or equal to a first threshold; creating a first partition having context groups having a number of data items greater than or equal to the first threshold; averaging the ratings for interests in the data items in the context groups in the first partition, resulting in each context group in the first partition being a cluster; and deriving a user's interest by comparing a current context to a context group in the first partition.