The reason for such increase in structure is not quite a particular decision of ours, but a consequence of using a sound grammar under the TAG grammatical formalism.
9 having concluded our manifesto, we understand that algorithms that try to keep precision as high as the recall necessarily have losses in recall compared to if they ignored the precision, and therefore in order to have fair comparison with them and to improve the credibility of our results, we flattened the parse trees in a post-processing step, using a simple rule-based technique on top of some frequency measures for individual grammar trees gathered by (Xia, 2001) and the result is presented in the bottom lines of the table.