1. A method for generating explanatory summaries, comprising the steps of: extracting features from text of text lists from summaries; evaluating explanatoriness of text, wherein evaluating the explanatoriness of text includes evaluating the features of the text, including at least the step of evaluating the discriminativeness of the features of the text by comparing the text to a first text data set, wherein the first text data set is derived from a topic label; and ranking the text based on the explanatoriness evaluation.