GETALP System : Propagation of a Lesk Measure through an Ant Colony Algorithm

This article presents the GETALP system for the participation to SemEval-2013 Task 12, based on an adaptation of the Lesk measure propagated through an Ant Colony Algorithm, that yielded good results on the corpus of Semeval 2007 Task 7 (WordNet 2.1) as well as the trial data for Task 12 SemEval 2013 (BabelNet 1.0). We approach the parameter estimation to our algorithm from two perspectives: edogenous estimation where we maximised the sum the local Lesk scores; exogenous estimation where we maximised the F1 score on trial data. We proposed three runs of out system, exogenous estimation with BabelNet 1.1.1 synset id annotations, endogenous estimation with BabelNet 1.1.1 synset id annotations and endogenous estimation with WordNet 3.1 sense keys. A bug in our implementation led to incorrect results and here, we present an amended version thereof. Our system arrived third on this task and a more fine grained analysis of our results reveals that the algorithms performs best on general domain texts with as little named entities as possible. The presence of many named entities leads the performance of the system to plummet greatly.