1. An information processing apparatus comprising: an extraction unit that extracts features of a selected document from an inverted index in which documents and features of the documents are associated; a retrieval unit that retrieves a document having any one of the features extracted by the extraction unit by the inverted index; a selection unit that selects a feature of the features corresponding to a plurality of retrieval results by the retrieval unit, the feature having a high effect of narrowing down the retrieval results; and a presentation unit that presents a combination of the features selected by the selection unit, as a retrieval condition.