USZEGED: Correction Type-sensitive Normalization of English Tweets Using Efficiently Indexed n-gram Statistics

This paper describes the framework applied by team USZEGED at the "Lexical Normalisation for English Tweets" shared task. Our approach first employs a CRFbased sequence labeling framework to decide the kind of corrections the individual tokens require, then performs the necessary modifications relying on external lexicons and a massive collection of efficiently indexed n-gram statistics from English tweets. Our solution is based on the assumption that from the context of the OOV words, it is possible to reconstruct its IV equivalent, as there are users who use the standard English form of the OOV word within the same context. Our approach achieved an F-score of 0.8052, being the second best one among the unconstrained submissions, the category our submission also belongs to.