Paşca's approach is to extract the words connected to the wh-word in the dependency representation of the question and look up those words in WordNet conceptual hierarchies that have been hand-mapped onto specific answer types.
indeed, Moldovan, Harabagiu, and colleagues earned the top score in the TREC 2002 QA track using a technique not described in Paşca's book: automated reasoning based on lexical chains derived from Word-Net glosses (Moldovan et al.