1. A system comprising: a text mining tool to process text in an electronic document to identify a topical expression and a polar expression in the electronic document; a text classifier to determine a topic of the topical expression and a polarity of the polar expression, to identify a relevance of the polar expression to the topical expression, and to generate a confidence score associated with the relevance of the polar expression to the topical expression; and a user interface to display the topical expression with the polar expression and the confidence score to a user.