Task #10: English Lexical Substitution Task

Diana McCarthy and Roberto Navigli

WSD has been described as a task in need of an application. Whilst researchers believe that it will ultimately prove useful for applications which need some degree of semantic interpretation, the jury is still out on this point. One problem is that WSD systems have been tested on fine-grained inventories, rendering the task harder than it need be for many applications (Ide and Wilks, 2006). A significant problem is that there is no clear choice of inventory for any given task (other than the use of a parallel corpus for a specific language pair for a machine translation application).

We propose a substitution task where the task for both annotators and systems is to find a substitute for the target word in the test sentence. Systems will have to identify candidate synonyms for a given word, and identify which fits best in a given context, thus requiring some discrimination between contexts. The task could be performed using a predefined inventory, such as WordNet, but we hope that it will also be a useful task for unsupervised systems which define meanings automatically from the data e.g. (Schütze,1998; Pantel and Lin, 2002).

The annotators will be asked to use single words as substitutes where possible but be instructed that they can provide either a phrase if one fits perfectly, or a slightly more general word if necessary. They will also be asked to identify where the word in the sentence is an integral part of a phrase. We hope that this will provide useful data for multiword evaluation however scores will be reported for i) all items, ii) single word (targets and subsitutes) and iii) multiwords. Thus systems not wishing to deal with multiwords will have scores reported for the subset of data where subjects have not identified multiwords in the target sentences and where the substitutes provided are "single word" items.


Ide, N. and Wilks, Y. (2006). Making Sense About Sense. In Agirre, E., Edmonds, P. (Eds.), Word Sense Disambiguation: Algorithms and Applications, Springer.

Pantel, P. and Dekang, L. 2002. Discovering Word Senses from Text. In Proceedings of ACM Conference on Knowledge Discovery and Data Mining (KDD-02). pp. 613-619. Edmonton, Canada.

Schütze, H. (1998) Automatic Word Sense Discrimination. In Computational Linguistics. 24 (1) pp97-123