Facts may be stubborn things, as John Adams once put it, but at least they're easy to compute. From a data-processing perspective, opinions are much more stubborn.
 
In recent years, the Web has created a bull market in human opinion: movie reviews, product ratings, restaurant recommendations, and all kinds of other viewpoints expressed in articles, blogs, discussion groups, and elsewhere. As the Web accumulates more and more data, many of us rely on each other's opinions as a filter to help us make informed decisions. For many businesses, customer opinions have become a type of virtual currency that can make or break their products. As opinion data plays an increasingly important role on the Web, however, computer scientists are discovering the limitations of traditional text analytics algorithms for sorting opinions from raw facts.
 
Read the entire ACM article.