IMG_20160518_193328 Refuse To Permit Us to Obtain a Refuse Permit
Diana demonstrates that NLTK -- Python Natural Language Toolkit -- correctly identifies parts of speech in the sentence "They refuse to permit us to obtain a refuse permit". As you can see, it identifies the first "refuse" as "VBG" (verb), and the first "permit" as "VB" (verb), but the second "refuse" and "permit" instances as "NN" (noun).
Identifying parts of speech was one of the basic natural language processing actions you can do with NLTK.
Then we ventured deeper into natural language processing to discuss where and how it is used, including such fields as sentiment analysis. Diana talked about challenges present in those fields, such as for example determining similarity between concepts. We need to be able to handle that so as to extract accurate meanings from texts. This is where ontologies can be handy.