1. A method comprising: (a) receiving an input query including one or more keywords and one or more entity types; (b) searching a database that indexes keywords and instances of entities having entity types in a collection of documents, the searching including searching for documents having the keywords and entities with the entity types in the input query; (c) aggregating a respective score for each of a plurality of entity tuples across the plurality of documents; (d) normalizing the aggregated scores, each respective normalized score providing a ranking of a respective entity tuple, relative to other entity tuples, as an answer to the input query; (e) outputting a list, including a subset of the entity tuples having the highest normalized scores among the plurality of entity tuples, to a storage or display device or a network.