As in the motivating example for the use of POS tagging, it was in the case of the verb use of ``love'' (``I love this movie'') that conveyed sentimental information, rather than the adjective use of the word. Interestingly, Pang did not include results for training only on verbs. Even more interestingly, despite the motivating example, verbs under-performed all other tests, while still being consistently better than random. The tests ranged from 60% to 67% accuracy, even sometimes doing worse than the 64% accurate human-based classifier from Pang 2002. We suspect this is in part due to the sparsity of features when only using verbs, as there were on average 37.2 verbs and 55.7 adjectives per review.

Pranjal Vachaspati 2012-02-05