by Jeff Elmore
Many of you are probably familiar with NLTK, the wonderful Natural Language Toolkit for Python. You may not be familiar with Linkgrammar, which is a sentence parsing system created at Carnegie Melon university. Linkgrammar is quite robust and works "out of the box" in a way that NLTK does not for sentence parsing.
NLTK is a fantastic library with broad capabilities. But often I find that I want something that will just do what I want without my having to figure out all of the details. An example of this is sentence parsing. A quick google search for parsing sentences with NLTK returns a number of articles describing how to write your own grammar and define a parser based on that grammar and parse sentences. This is great for toy problems and education, but if you actually need to parse sentences "from the wild," writing your own grammar is a huge undertaking.
Enter Linkgrammar. Linkgrammar was developed at Carnegie Melon university and is now maintained by the developers of Abiword as the basis for their grammar checking capabilities. It works nicely out of the box and is tolerant of irregularities found in authentic text.
7th–15th March 2012