Java Stanford NLP: Part of Speech labels?

Question

The Stanford NLP, demo'd here, gives an output like this:

Colorless/JJ green/JJ ideas/NNS sleep/VBP furiously/RB ./.

What do the Part of Speech tags mean? I am unable to find an official list. Is it Stanford's own system, or are they using universal tags? (What is JJ, for instance?)

Also, when I am iterating through the sentences, looking for nouns, for instance, I end up doing something like checking to see if the tag .contains('N'). This feels pretty weak. Is there a better way to programmatically search for a certain part of speech?

Answer 1

Just from exploring the site, http://nlp.stanford.edu/software/parser-faq.shtml looks like it might have useful information for you, or at least point you in the correct direction for more documentation.

Answer 2

They seem to be Brown Corpus tags.

Answer 3

I don't know if you are locked into that Library, or even Java. If you get a chance, check out this book:

Natural Language Processing with Python

Its been very handy for some of my projects. I love Java, but I think NLP needs a far more interactive language to be productive and not go mad. The book uses the Natural Language Toolkit. Lisp is also a beautiful language for NLP, but a little more difficult to set up.

Wish you best of luck.

Answer 4

The Penn Treebank Project. Look at the Part-of-speech tagging ps.

JJ is adjective. NNS is noun, plural. VBP is verb present tense. RB is adverb.

That's for english. For chinese, it's the Penn Chinese Treebank. And for german it's the NEGRA corpus.

1. CC Coordinating conjunction
2. CD Cardinal number
3. DT Determiner
4. EX Existential there
5. FW Foreign word
6. IN Preposition or subordinating conjunction
7. JJ Adjective
8. JJR Adjective, comparative
9. JJS Adjective, superlative
10. LS List item marker
11. MD Modal
12. NN Noun, singular or mass
13. NNS Noun, plural
14. NNP Proper noun, singular
15. NNPS Proper noun, plural
16. PDT Predeterminer
17. POS Possessive ending
18. PRP Personal pronoun
19. PRP$ Possessive pronoun
20. RB Adverb
21. RBR Adverb, comparative
22. RBS Adverb, superlative
23. RP Particle
24. SYM Symbol
25. TO to
26. UH Interjection
27. VB Verb, base form
28. VBD Verb, past tense
29. VBG Verb, gerund or present participle
30. VBN Verb, past participle
31. VBP Verb, non­3rd person singular present
32. VBZ Verb, 3rd person singular present
33. WDT Wh­determiner
34. WP Wh­pronoun
35. WP$ Possessive wh­pronoun
36. WRB Wh­adverb