Part of Speech Tagging
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Summary
Part of Speech Tagging (or POS Tagging for short) is a task in the field of computational linguistics which looks at marking a text corpus with the associated word categories known as parts of speech to words.
Common Approaches
Some common approaches to POS Tagging include the following:
- Hidden Markov Models based approaches
- Dynamic Programming/Viterbi-like algorithms (DeRose & Church)
- Unsupervised approaches: Brill Tagger (Transformation-based learning), Constraint Grammar, Forward-Backward
Example Systems
- FastTag - open source implementation of Brill Tagger
- OpenNLP Tagger - based on maximum entropy
- CRF Tagger - based on conditional random fields
- LingPipe - tool kit that contains models for POS tagging