]> 2010-11-09T12:30:00-05:00 2010-11-09T14:00:00-05:00 In this talk I will outline the problem by presenting new experiments supporting the claim that topical sentiment is expressed by the sum of a large number of very weak signals. As a partial solution I will present a fast, statistically grounded technique to determine sentimental word orientation for a given topic. Then I will present preliminary results using document synthesis to bootstrap topical sentiment polarity classifiers at run time. ]]>