1. A method comprising: identifying a word weight for each word in a corpus based on a relevance of each word; receiving a document that comprises a plurality of sentences; assigning to each word in the plurality of sentences a tag indicative of a part of speech of the word; calculating a topic weight for each sentence based on the tags of the words in the sentence, wherein calculating the topic weight further comprises: calculating an event weight for the sentence based on the tags of the words in the sentence; calculating an entity weight for the sentence based on the tags of the words in the sentence; and calculating a sentiment weight for the sentence based on the tags of the words in the sentence; calculating a sentence weight for each sentence based on a sum of the word weights of the words in the sentence, the topic weight for the sentence, and a position weight of the sentence within a paragraph; selecting the sentence with a highest sentence weight as a title for the document; and causing the title to be presented with the document to a user.