To Use a Treebank or Not - Which Is Better for Hypernym Extraction?

We compare two processing methods for a single natural language processing task. One uses a treebank created with a full parser while the other restricts itself to lexical and part-of-speech information. We show that for the task under investigation, automatic extraction of hypernym-hyponym pairs from text, the former does not outperform the latter. We compare the output of the two approaches and look for an explanation for this unexpected result.