1. A system comprising: a storage device to store a respective semantic projection for each of a plurality of resources, for each of a plurality of sets of user interests and for each of a plurality of user contexts, each respective semantic projection conforming to a common semantic projection model; and a processor to: determine a similarity of a semantic projection of a set of interests of a first user to a semantic projection of a first resource includes: determination of a similarity of a semantic projection of a set of static interests associated with the first user to the semantic projection of the first resource; determination of a similarity of a semantic projection of a set of dynamic interests associated with the first user and a first context to the semantic projection of the resource, and wherein the determination of the semantic interest of the first user for the first resource in the first context is based on the similarity of the semantic projection of the set of static interests associated with the first user to the semantic projection of the resource, and on the similarity of the semantic projection of the set of dynamic interests associated with the first user and the first context to the semantic projection of the resource; determine a semantic interest of the first user for the first resource in the first context based on the similarity of the semantic projection of the set of the interests of the first user to the semantic projection of the first resource; and determine an interest measure associated with the first user, the first resource and the first context based on a rating prediction for the first user to the first resource in the first context and on the determined semantic interest of the first user for the first resource in the first context.
1. A system comprising: a storage device to store a respective semantic projection for each of a plurality of resources, for each of a plurality of sets of user interests and for each of a plurality of user contexts, each respective semantic projection conforming to a common semantic projection model; and a processor to: determine a similarity of a semantic projection of a set of interests of a first user to a semantic projection of a first resource includes: determination of a similarity of a semantic projection of a set of static interests associated with the first user to the semantic projection of the first resource; determination of a similarity of a semantic projection of a set of dynamic interests associated with the first user and a first context to the semantic projection of the resource, and wherein the determination of the semantic interest of the first user for the first resource in the first context is based on the similarity of the semantic projection of the set of static interests associated with the first user to the semantic projection of the resource, and on the similarity of the semantic projection of the set of dynamic interests associated with the first user and the first context to the semantic projection of the resource; determine a semantic interest of the first user for the first resource in the first context based on the similarity of the semantic projection of the set of the interests of the first user to the semantic projection of the first resource; and determine an interest measure associated with the first user, the first resource and the first context based on a rating prediction for the first user to the first resource in the first context and on the determined semantic interest of the first user for the first resource in the first context. 8. A system according to claim 1 , wherein determination of the similarity of the semantic projection of the set of the interests of the first user to the semantic projection of the first resource comprises: determination of a first branch of the semantic projection of the set of interests of the first user and a second branch of the semantic projection of the first resource which is comparable to the first branch; determination of a first one or more sub-trees for the first branch, the first one or more sub-trees comprising first explicit concepts and parent concepts thereof; determination of a second one or more sub-trees for the second branch, the second one or more sub-trees comprising second explicit concepts and parent concepts thereof; and determination of a similarity between the first branch and the second branch based on a weighted average of a proximity of weights of concepts of the first one or more sub-trees and weights of corresponding concepts of the second one or more sub-trees.