1. A method, comprising: receiving a graph, with a subset of the graph being a subject graph of subject nodes that includes at least one or more subjects linked to one or more other subjects, the graph including one or more objects each linked to one or more subjects in the subject graph, each subject being a user, each object being a content item, and each edge in the graph representing a citation and each citation representing an expression of opinion or description by a subject on an object; determining reputation scores for one or more subjects based on connections among the subjects in the graph, wherein the reputation scores indicate the reputation of the subjects; selecting only a subset of citations for each object from among all the citations citing each object, the content of the citations in the selected subset matching one or more of the search terms for the search query, a different subset of citations being selectable for a same object when a different search query is provided; assigning citation scores to any subset of a plurality of objects, the citation scores indicating relevance of the objects cited by citations and are determined based at least in part on matching one or more search terms with the content of the citations of the objects by the one or more subjects, the selection scores for an object computed for each search query based on a subset of subjects citing the object, with the subjects in the subset being the subjects of previously selected subsets of citations to each object; combining the citation scores for the objects and the reputation scores for the subjects citing the objects to calculate selection scores for the objects determined based on matching the one or more search terms with the content of the citations, the selection scores for an object computed for each search query based on a subset of subjects citing the object, with the subjects in the subset being the subjects of previously selected subsets of citations to each object, a different selection score computed for the same object when a different search query is provided; and selecting and ranking the objects based on the selection scores of the objects, a different ranking computed for a same set or overlapping sets of objects when the search query is different.