A method and system for selecting data from a source text corpus for training a semantic data analysis system. The method includes selecting an item of the text corpus, wherein the item includes at least one section. The method includes extracting a section of the at least one section of the item. The method also includes determining a length of the section of the at least one section of the item. Based on the length of the section being greater than a predetermined amount, the method includes subdividing the section into a plurality of fragments. Each fragment of the plurality of fragments is deemed to be similar to each other. Further, the method includes building a training set based on the plurality of fragments. The training set is used to train the semantic data analysis system.