21. A method in a content recommendation computing system, the method comprising: presenting a first user interface control that is configured to create a new entity collection in response to received user selection of indications of multiple named entities and suggest one or more additional entities to add to an existing collection; presenting a second user interface control that displays information about collections created by multiple different users of the content recommendation computing system; receiving from a user via the first user interface control an indication of a collection including multiple named entities that are each referenced by one or more of multiple articles indexed by the content recommendation computing system and that are each electronically represented in the content recommendation computing system, the collection being separate from the multiple articles indexed by the content recommendation computing system; and under control of the content recommendation computing system, automatically recommending one or more additional entities based on the collection to be added to the collection, by: determining shared characteristics of the multiple entities, wherein each shared characteristic is the same for each of the multiple entities of the collection, the shared characteristics including common facets and common key terms common to the multiple entities of the collection, wherein the common facets are category values, type values, and/or characteristic values of the multiple entities and are sub-type values of a top-level entity type electronically represented by the content recommendation computing system; determining a plurality of additional entities by constructing a query configured to discover relationships expressed in articles, wherein the plurality of additional entities includes at least: a first entity that appears in an article in a relationship with one of the common facets, wherein the first entity appears in the article in a relationship with one of the common facets when the first entity appears as a subject or object of a first subject-verb-object relation present in the article in which the one of the common facets appears as the other of the subject or object of the first subject-verb-object relation, a second entity that appears in an article in context with one of the common key terms, and a third entity that appears in an article in a relationship with one of the multiple entities and in the article in context with another one of the multiple entities, wherein the third entity appears in the article in a relationship with one of the multiple entities when the third entity appears as a subject or object of a second subject-verb-object relation present in the article in which the one of the multiple entities appears as the other of the subject or object of the second subject-verb-object relation; ordering the determined plurality of additional entities, based on entity frequency counts of frequency each entity appears in the indexed articles and on whether the determined additional entities share one or more of the common facets; presenting on the first user interface control the ordered plurality of entities as suggested additions to the collection; modifying the collection by adding one of the ordered plurality of entities to the collection, the added entity selected by a user via the first user interface control; automatically processing the modified collection to determine one or more of the indexed articles that are related to at least some of the multiple entities of the modified collection, wherein processing the modified collection includes determining whether one of the multiple entities appears in an article in a relationship with a facet common to entities of the modified collection and in the article in context with key terms common to the entities of the modified collection, wherein the one of the multiple entities appears in an article in a relationship with the facet common to entities of the modified collection when the one of the multiple entities appears as a subject or object of a third subject-verb-object relation present in the article in which the facet common to the entities of the modified collection appears as the other of the subject or object of the third subject-verb-object relation; storing the modified collection; and storing indications of the determined articles.
21. A method in a content recommendation computing system, the method comprising: presenting a first user interface control that is configured to create a new entity collection in response to received user selection of indications of multiple named entities and suggest one or more additional entities to add to an existing collection; presenting a second user interface control that displays information about collections created by multiple different users of the content recommendation computing system; receiving from a user via the first user interface control an indication of a collection including multiple named entities that are each referenced by one or more of multiple articles indexed by the content recommendation computing system and that are each electronically represented in the content recommendation computing system, the collection being separate from the multiple articles indexed by the content recommendation computing system; and under control of the content recommendation computing system, automatically recommending one or more additional entities based on the collection to be added to the collection, by: determining shared characteristics of the multiple entities, wherein each shared characteristic is the same for each of the multiple entities of the collection, the shared characteristics including common facets and common key terms common to the multiple entities of the collection, wherein the common facets are category values, type values, and/or characteristic values of the multiple entities and are sub-type values of a top-level entity type electronically represented by the content recommendation computing system; determining a plurality of additional entities by constructing a query configured to discover relationships expressed in articles, wherein the plurality of additional entities includes at least: a first entity that appears in an article in a relationship with one of the common facets, wherein the first entity appears in the article in a relationship with one of the common facets when the first entity appears as a subject or object of a first subject-verb-object relation present in the article in which the one of the common facets appears as the other of the subject or object of the first subject-verb-object relation, a second entity that appears in an article in context with one of the common key terms, and a third entity that appears in an article in a relationship with one of the multiple entities and in the article in context with another one of the multiple entities, wherein the third entity appears in the article in a relationship with one of the multiple entities when the third entity appears as a subject or object of a second subject-verb-object relation present in the article in which the one of the multiple entities appears as the other of the subject or object of the second subject-verb-object relation; ordering the determined plurality of additional entities, based on entity frequency counts of frequency each entity appears in the indexed articles and on whether the determined additional entities share one or more of the common facets; presenting on the first user interface control the ordered plurality of entities as suggested additions to the collection; modifying the collection by adding one of the ordered plurality of entities to the collection, the added entity selected by a user via the first user interface control; automatically processing the modified collection to determine one or more of the indexed articles that are related to at least some of the multiple entities of the modified collection, wherein processing the modified collection includes determining whether one of the multiple entities appears in an article in a relationship with a facet common to entities of the modified collection and in the article in context with key terms common to the entities of the modified collection, wherein the one of the multiple entities appears in an article in a relationship with the facet common to entities of the modified collection when the one of the multiple entities appears as a subject or object of a third subject-verb-object relation present in the article in which the facet common to the entities of the modified collection appears as the other of the subject or object of the third subject-verb-object relation; storing the modified collection; and storing indications of the determined articles. 23. The method of claim 21 wherein determining the plurality of additional entities includes determining a plurality of additional entities that each appear in an article in a relationship with one of the common facets and in the article in context with one of the common key terms.