In this paper we present a user-centered approach for defining the dependency syntactic specification for a treebank. We show that by collecting information on syntactic interpretations from the future users of the treebank, we can model so far dependency-syntactically undefined syntactic structures in a way that corresponds to the users ’ intuition. By consulting the users at the grammar definition phase we aim at better usability of the treebank in the future. We focus on two complex syntactic phenomena: elliptical comparative clauses and participial NPs or NPs with a verbderived noun as their head. We show how the phenomena can be interpreted in several ways and ask for the users ’ intuitive way of modeling them. The results aid in constructing the syntactic specification for the treebank. 1