As seen here…
“An apology is due – until today, Digg’s search has been pretty terrible. I’m really excited to announce that our search no longer sucks. In fact, I think it’s awfully good but you should try it out and judge for yourself.
Our primary focus is to give you the best possible stories at the top of the results right away. The first thing you’ll notice is an improved user interface but don’t let that fool you, there are significant improvements under the hood. We weight searches on a number of factors including timeliness, Digg counts, keywords, and others.”