Abstract (EN):
The automatic processing of microblogging messages may be problematic, even in the case of very elementary operations such as tokenization. The problems arise from the use of non-standard language, including media-specific words (e.g. "2day", "gr8", "tl;dr", "loool"), emoticons (e.g. "(ò-ó)", "(=∧-∧=)"), non-standard letter casing (e.g. "dr. Fred") and unusual punctuation (e.g. "⋯. ..", "!!?", "","). Additionally, spelling errors are abundant (e.g. "I;m"), and we can frequently find more than one language (with different tokenization requirements) in the same short message. For being efficient in such environment, manually-developed rule-based tokenizer systems have to deal with many conditions and exceptions, which makes them difficult to build and maintain. We present a text classification approach for tokenizing Twitter messages, which address complex cases successfully and which is relatively simple to set up and maintain. For that, we created a corpus consisting of 2500 manually tokenized Twitter messages - a task that is simple for human annotators - and we trained an SVM classifier for separating tokens at certain discontinuity characters. For comparison, we created a baseline rule-based system designed specifically for dealing with typical problematic situations. Results show that we can achieve F-measures of 96% with the classification-based approach, much above the performance obtained by the baseline rule-based tokenizer (85%). Also, subsequent analysis allowed us to identify typical tokenization errors, which we show that can be partially solved by adding some additional descriptive examples to the training corpus and re-training the classifier. © 2010 ACM.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
7