Summarizing Blog Entries versus News Texts

As more and more people are expressing their opinions on the web in the form of weblogs (or blogs), research on the blogosphere is gaining popularity. As the outcome of this research, different natural language tools such as querybased opinion summarizers have been developed to mine and organize opinions on a particular event or entity in blog entries. However, the variety of blog posts and the informal style and structure of blog entries pose many difficulties for these natural language tools. In this paper, we identify and categorize errors which typically occur in opinion summarization from blog entries and compare blog entry summaries with traditional news text summaries based on these error types to quantify the differences between these two genres of texts for the purpose of summarization. For evaluation, we used summaries from participating systems of the TAC 2008 opinion summarization track and updated summarization track. Our results show that some errors are much more frequent to blog entries (e.g. topic irrelevant information) compared to news texts; while other error types, such as content overlap, seem to be comparable. These findings can be used to prioritize these error types and give clear indications as to where we should put effort to improve blog