Yahoo piggybacks on Twitter for updated Delicious

Yahoo's social bookmarking service Delicious today has received an upgrade with a Twitter mashup component originally designed for Yahoo News.

TweetNews took Yahoo News articles (which are ordered chronologically) and compared them to Twitter's trending topics (which are based on a subject's popularity.) The result was a news search that could not only determine the freshest articles, but also those based on the most popular subject at the moment. The app also used social commentary to determine the pertinence of authoritative news sources when determining search results.

As Yahoo architect and BOSS team member Vik Singh said, "Freshness (especially in the context of search) is a challenging problem. Traditional PageRank style algorithms don't really work here as it takes time for a fresh URL to garner enough links to beat an older high ranking URL. One approach is to use cluster sizes as a feature for measuring the popularity of a story (i.e., Google News). Although quite effective in my opinion, this may not be fast enough all the time. For the cluster size to grow requires other sources to write about the same story."

So if only one respected source wrote about a topic that was being talked about a lot on Twitter, that lone story would be pushed up in rank on Yahoo News.

Now that Yahoo's main search is soon to be powered by Microsoft's Bing, the TweetNews technology is not being wasted. Today, Singh announced that it has been applied to Delicious, where Twitter trends impact recently bookmarked links. The new system is running live right now under the "Fresh" tab.

"For this new Fresh homepage, our system displays recently bookmarked links and Tweeted messages focused mostly on technology, Web, politics, and media," Singh said today. "Underneath the hood, Fresh factors several features into the ranking like related bookmark and tweet counts, by leveraging BOSS to filter for high quality results, as well as stitches tweets to related articles even if the tweets do not provide matching URLs (as ~81% of tweets do not contain URLs). Try clicking the 'x Related Tweets' link for any given story to see the Twitter conversation appear instantly inline."