We present an interactive query formulation technique
which enables exploitation not only of structural properties
of data but also of semantic constraints as posed by the contents of data. The technique aims at the formulation of a semantically consistent or meaningful query by the end-user without any previous knowledge of syntax formalisms and
data model semantics. This has been achieved by end-user
guidance in that an inference engine suggests semantically
rich query terms for further consideration by the end-user.
The set of suggested terms at each interaction stage comply
with the already considered query terms with respect to
structure and contents based semantics. Assignment or selection of operational terms are also allowed, if operational semantics comply with the semantics of data. The interactive query formulation component has been implemented in Java and runs on the client side of a client/server based query answering system architecture.