Uses/Applications of Part-of-speech-tagging (POS Tagging)

Question

I understand the implicit value of part-of-speech tagging and have seen mentions about its use in parsing, text-to-speech conversion, etc.

Could you tell me how is the output of a PoS tagger formated ? Also, could you explain how is such an output used by other tasks/parts of an NLP system?

Dynasty

I am interested more in knowing: Which stages/tasks of a typical NLP pipeline may utilize the output of a POS tagger--and how they utilize it? – Dynasty

Answer 1

One purpose of PoS tagging is to disambiguate homonyms. For instance, take this sentence :

I fish a fish

The same sentence in french would be Je pêche un poisson. Without tagging, fish would be translated the same way in both case, which would lead to a wrong traduction. However, after PoS tagging, the sentence would be

I_PRON fish_VERB a_DET fish_NOUN

From a computer point of view, both words are now distinct. This wat, they can be processed much more efficiently (in our example, fish_VERB will be translated to pêche and fish_NOUN to poisson).

Astern

Thanks to both of you for the example. Looking forward to more examples/applications. Best Regards... – Dynasty

Answer 2

Basically, the goal of a POS tagger is to assign linguistic (mostly grammatical) information to sub-sentential units. Such units are called tokens and, most of the time, correspond to words and symbols (e.g. punctuation).

Considering the format of the output, it doesn't really matter as long as you get a sequence of token/tag pairs. Some POS taggers allow you to specify some specific output format, others use XML or CSV/TSV, and so on.

Baumbaugh