Abstract : This paper reports our participation in the INEX 2008 Ad- Hoc Retrieval track. We investigated the effect of multiword terms on retrieval effectiveness in an interactive query expansion (IQE) frame- work. The IQE approach is compared to a state-of-the-art IR engine (in this case Indri) implementing a bag-of-word query and document rep- resentation, coupled with pseudo-relevance feedback (automatic query expansion(AQE)). The performance of multiword query and document representation was enhanced when the term structure was relaxed to ac- cept the insertion of additional words while preserving the original struc- ture and word order. The search strategies built with multiword terms coupled with QE obtained very competitive scores in the three Ad-Hoc tasks: Focused retrieval, Relevant-in-Context and Best-in-Context.