Abstract
This paper outlines a measure of language similarity based on structural similarity of surface syntactic dependency trees. Unlike the more tradi- tional string-based measures, this measure tries to reflect deeper correspondences among languages.
The development of this measure has been inspired by the experience from MT of syntactically similar languages. This experience shows that the lexical similarity is less important than syntactic similarity.
This claim is supported by a number of examples illustrating the problems which may arise when a measure of language similarity relies too much on a simple similarity of texts in different languages.