National Public Radio had a topic wherein they discussed the relative accuracy, knowing it was often up for debate, of Wikipedia was the subject. They estimated that the Wikipedia was at about 72-73% while the Brittanica was at about 75%, owing largely to disputes, aging of data, and the like. Facts do change, and it's a really big job for a publisher to remain "on top" of that stuff.

Unfortunately, the lunatic (or ignorant) fringe has its impact on Wikipedia.

Now, my spewing forth these "facts" should be taken with a grain of salt, as I'm operating out of what once was a "steel-trap" memory, but has more recently begun to resemble a polyethylene colander, at times. That, sadly, is also what impacts the accuracy of Wikipedia, i.e. well intentioned, but, perhaps, faulty-memoried, individuals making corrections, updates, etc.

RE