1. A computer program product for comparing and optionally recommending works of literature, comprising: a tangible, computer readable memory storage device; program instructions stored by the computer readable memory storage device for causing a processor to, when executed, perform steps of: access a first cluster model for a first work of literature; access at least a second cluster model for at least a second work of literature; compare the first and at least second cluster models for similarities; generate a score according to degrees of match between the first and second cluster models; and produce a recommendation score regarding the second work of literature as being comparable or similar to the first work of literature; wherein the first and second cluster models reflect clusters of concepts and longitudinal patterns or consistency trends of elements in the clusters across multiple segments of each respective work of literature.