On 7/6/11 9:27 AM, Dmitri O.Kondratiev wrote:
Hi, Continuing my search of Haskell NLP tools and libs, I wonder if the following Haskell libraries exist (googling them does not help): 1) End of Sentence (EOS) Detection. Break text into a collection of meaningful sentences.
Depending on how you mean, this is either fairly trivial (for English) or an ill-defined problem. For things like determining whether the "." character is intended as a full stop vs part of an abbreviation; that's trivial. But for general sentence breaking, how do you intend to deal with quotations? What about when news articles quote someone uttering a few sentences before the end-quote marker? So far as I'm aware, there's no satisfactory definition of what the solution should be in all reasonable cases. A "sentence" isn't really very well-defined in practice.
2) Part-of-Speech (POS) Tagging. Assign part-of-speech information to each token.
There are numerous approaches to this problem; do you care about the solution, or will any one of them suffice? I've been working over the last year+ on an optimized HMM-based POS tagger/supertagger with online tagging and anytime n-best tagging. I'm planning to release it this summer (i.e., by the end of August), though there are a few things I'd like to polish up before doing so. In particular, I want to make the package less monolithic. When I release it I'll make announcements here and on the nlp@ list.
3) Chunking. Analyze each tagged token within a sentence and assemble compound tokens that express logical concepts. Define a custom grammar.
4) Extraction. Analyze each chunk and further tag the chunks as named entities, such as people, organizations, locations, etc.
Any ideas where to look for similar Haskell libraries?
I don't know of any work in these areas in Haskell (though I'd love to hear about it). You should try asking on the nlp@ list where the other linguists and NLPers are more likely to see it. -- Live well, ~wren