  In Knowledge Management, variations in information expressions have proven a
real challenge. In particular, classical semantic relations (e.g. synonymy) do
not connect words with different parts-of-speech. The method proposed tries to
address this issue. It consists in building a derivational resource from a
morphological derivation tool together with derivational guidelines from a
dictionary in order to store only correct derivatives. This resource, combined
with a syntactic parser, a semantic disambiguator and some derivational
patterns, helps to reformulate an original sentence while keeping the initial
meaning in a convincing manner This approach has been evaluated in three
different ways: the precision of the derivatives produced from a lemma; its
ability to provide well-formed reformulations from an original sentence,
preserving the initial meaning; its impact on the results coping with a real
issue, ie a question answering task . The evaluation of this approach through a
question answering system shows the pros and cons of this system, while
foreshadowing some interesting future developments.
