A new study from Cornell University shows the life-cycle of news reports online and the overall trend and spread of stories and events among the various online media mostly focusing on the differences between traditional established news outlets and blogs. The study found that, overall, blogs lagged behind traditional news outlets on average by 2.5 hours.

The study, called “Meme-tracking and the Dynamics of the News Cycle,” focused on the way small phrases or quotes spread online and on what and how news outlets picked them up. It used data from a three-month period in the height of the US presidential campaign between August 1, 2008 and October 31, 2008 and involved 1.65 million different sites and about 1 million documents per day both blog posts and news stories amounting to 90 million documents over the period. The data was analyzed using advanced algorithms looking for repeating phrases.

Its results were somewhat unsurprising, finding that traditional media typically leads in the online environment too, with most popular phrases originating from large mainstream news outlets which are later spread by the blogosphere apparently backing up claims usually made by some traditional journalists who have a general distrust of blogs as news source. However, the study also found that a few blogs were actually the first to report a story that would later gain greater traction online, this time giving arguments to those who put forward blogging as the future of journalism.

But even the authors of the study were cautious with the findings, citing that using the same quotes does not necessarily translate into the documents being the same news story but this is the best way currently to translate ideas and story lines into something computers can track and measure. And while it is a landmark study on account of its scale and scope, the fact is that the medium may have already changed significantly since last fall mostly due to the rise of Twitter.