  Data from Online Social Networks (OSNs) are providing analysts with an
unprecedented access to public opinion on elections, news, movies etc. However,
caution must be taken to determine whether and how much of the opinion
extracted from OSN user data is indeed reflective of the opinion of the larger
online population. In this work we study this issue in the context of movie
reviews on Twitter and compare the opinion of Twitter users with that of the
online population of IMDb and Rotten Tomatoes. We introduce new metrics to show
that the Twitter users can be characteristically different from general users,
both in their rating and their relative preference for Oscar-nominated and
non-nominated movies. Additionally, we investigate whether such data can truly
predict a movie's box-office success.
