Introduction to the special issue on multiword expressions: Having a crack at a hard nut

Multiword expressions are an integral part of language. Their heterogeneous characteristics have proved a challenge to both linguistic and computational analysis. Their importance to language technology has long been recognised. In this special issue we include ten papers which propose a variety of approaches for finding and handling these expressions, both for building general purpose lexical resources and in the context of specific applications. In this introduction we give a brief summary of what multiword expressions are, the challenges that they pose and some open areas of research. We then highlight the contributions that the ten papers make to these areas. Preprint submitted to Elsevier Science 9 March 2005