The Lexical Substitution task at EVALITA 2009

This paper describes the Italian Lexical Substitution task organised for EVALITA 2009. In this task, given a word in a specic context, the participant is asked to provide the synonyms which best t in that context. The motivation behind the task, its objectives, the data prepared and distributed to participants, the baselines developed and the evaluation measures used are introduced. The results obtained both by the participating systems and by the baselines are presented. Finally, the dierent methodologies and resources used by the participants' systems and the results obtained by each of them are discussed.