In choosing the top articles of any year, there are always a few knobs to turn. A top article traffic-wise, for example, could be one from a prior year, since we have articles with millions of readers, and since we carry some press release stuff it could be one of those, and one person may have two.And since Science 2.0 is all member-driven, no employees or corporate or government overlord, the people who might pick the candidates would most likely be the most active, and therefore one of the candidates. So instead we take it out of anyone's hands and just went by number of readers (not number of pageviews, since a controversial article can generate a lot more of those). And only one per author. And only 5 since, really, no one is reading 10 articles on a list.