Matt Cutts, Google’s head of search spam, answers a question about duplicate content in his latest webmaster help video where a user writes in to ask:
If you had to deal with short-term duplicated content on a news site (perhaps publishing a story on two different URLs over one day), what would you do in order to avoid any penalty from a duplicate content filter?
Matt answers the question assuming the user who is asking it has honest intentions and engaging in white hat practices. Short-term duplicate content sometimes arises when there’s breaking news that needs to be covered across multiple URLs. When that happens, Matt recommends making use of the “rel=canonical” tag.
Having multiple copies of a short news story on different URLs divides Page Rank amongst those stories. If these stories are on the exact same piece of news, then Matt says to use “rel=canonical” to point to one home URL for that story.
While the story is breaking Matt says it’s understandable that you’ll have multiple instances of that story spread across the web. When things settle down, having a “rel=canonical” tag in place indicates the preferred location on the web where you would like that information to sit.
If you do that, assuming you don’t have massive amounts of other duplicate content all over your site, then you should be able to avoid any kind of manual spam action for posting those breaking news stories on multiple URLs.
To hear Matt’s full response to the question in his own words, please see the video below: