Definition: Given a 'poster' sentence and a corresponding 'response' (often, from Facebook or Reddit)classify the sentiment of the given response into four categories: 1) Positive, 2) Negative, 3) Neutral, and 4) Mixed if it contains both positive and negative.
Input: Poster: Oil Spill Incident Facts as of 6/29/2010:  Responser: http://hotair.com/archives/2010/06/27/day-68-why-isnt-the-a-whale-in-the-gulf-yet
