Unsurprisingly, Britannica disagrees with Nature’s assessment. Here’s a snippet with a nod to Capt. Ridley’s Shooting Party’s point about opinions:
I’ll definitely agree that Britannica is far better written than Wikipedia. The quality of writing is probably what suffers worse from Wikipedia’s “create by committee” approach.
Unfortunately true. There are people who misunderstand the meaning of consensus. They feel it gives them a veto over anything they disagree with.
That said, bias is probably just as present in Britannica just less visible. An article written by a single author will quietly reflect his biases. In Wikipedia, the presense of multiple authors can lead to heated arguments but it also exposes different points of view.
There’s also a bias towards online cites. Some people refuse to accept a cite from a book because they can’t click on a link and read it.
You also get “The Politicals” who decide they like or don’t like a particular person or position or history bit and will NEVER let it be objective. And some of them have a lot of power.
I think Wikipedia is pretty useful - perhaps that’s because I don’t often have a need for a definitive, authoritative declaration on some matter of science, but rather, want a list of edible snail species, or need to know whether SuperAntiSpyware is classed as a rogue program, or is genuine.
The biggest problem I’ve encountered with Wikipedia is vandalism - I know there are all sorts of mechanisms - proposed and implemented - to try to counter it, but there’s still a lot of it about. Sure, it usually gets reverted fairly promptly, but until that happens, people will see the vandalised version.
The worst kind of vandalism is the subtle kind - for example, I was looking at the history of the article on Richard Branson - one obviously malicious edit added some insulting epithets to his name, but also changed some dates in the article - the next edit removed the epithets, but left the dates - and as far as I remember, the amended dates persisted right to the current version. I have no idea which date is correct - maybe the vandal did actually change it to the correct date, but it seems unlikely.
I teach college courses, and find that for some things Wikipedia is nice, and I equate it to Google Images for finding information - both are very quick, but neither can produce perfectly reliable results. But, if I quickly want a list of antibiotics and their class I can find a neat and tidy one there, without having to search through a dozen sites. Or if I want to know class/order/family information on certain organisms, or just fact-check. I like it for it’s formatting reliability - I can guarantee that every page is laid out the same, and know where to go very quickly to find the information I need. But I agree, a lot of the time the information is either too basic, or too complex (in that I can understand it only because I am in the field). I actually find the worst articles in the engineering/physics-type sections - it’s like I’m reading someone’s dissertation that has been copied and pasted online. Is it too much to ask for some sort of explanation before jumping into some huge equation?
Generally, for in-depth information, use good old-fashioned textbooks or websites written by experts in the field. I’m actually looking forward to this new site Google’s planning on putting out, where experts write articles. Maybe they’ll let me write a couple 
I can get lots of information online, and check it against another source. However, I read for pleasure as well as information. As a literary document, Britannica is far superior.
Wikipedia is ultimately handy for quickly checking information. As a user of the tool Wikipedia, it’s up to you to judge the validity of an article. Many “facts” stated in Wikipedia have [37] links to cites at the bottom of the page, where you can verify a claim with a third party - you can back up the Wikipedia claim by referencing a “more reliable” source(s), which would then give the particular Wikipedia article you’re reading more validity.
If it says [citation needed], perhaps you want to ignore what it says. If it has no reference at all, then maybe you want to use The Google to back up what it says (or you may want to do that anyhow).
I’d also like to add that when I do searches for knowledge type topics through search engines (Google, Yahoo, etc.), Wikipedia is often one of the first links on the list, many times the first or second. I know this doesn’t mean that the data on those articles is more accurate, but the way their placing algorithms work, it suggests that people who click to those Wikipedia articles through Google searches tend to stay there. Whether or not the data is correct, what that user read has now become fact in their head. Wikipedia is a powerful meme tool because it’s easier to reference (and lock down info as fact in your head), and more frequently referenced online, than EB.
On a humorous note, I heard of a shirt that says “wikipedia is always right.” I want to get that right above, “MySpace sucks. And Tom is not my friend.”
EB doesn’t have random Simpsons shit inserted into every goddamned page.
Sorry. I promise not to change the “black hole” entry again 
1.) Persistence – As has been mentioned, a Wikipedia entry can disappear tomorrow. Anything on the internet, on any site, is only slightly less ephemeral than a telephone call. People are now citing the internet in papers and journals, but I can tell they don’t like it. It’s not just prejudice that makes people prefer the paper-and-ink version that they know will be there when they need to confirm it.
2.) Traceability – You can trace the references in the EB, look at their references, and find out who wrote it. Wikipedia gives references (a good point in their favor), but I still don’t think you can find out who wrote the article, or if they had a significant bias.
3.) As mentioned above, the EB is consistent in style and coverage. Too much of the Internet lacks an editor, and Wikipedia is one sitgnificant example of this.
Finally, because of the way it’s constructed and written, people still don’t completely trut Wikipedia. I’ve found faults in it myself, and not just in partisan articles. Everyone I know (including me) says “Go to Wikipedia to look something up quickly – but always check the sources.”
Not that the EB is infallible. The most recent edition I checked still says that Betegeuse isn’t a variable star. That ought to be news to the people at the American Association of Variable Star Observers, who have about 100 years of records of its variations.
And the babelfished translations, which I’ve encountered both with English as the source language and with Spanish as the original.
…provided that one has a computer and an internet connection. But the EB - pay for it once and you can use it forever. This is not to deny the downsides of the EB, but there are some upsides.
When my kids had to do papers for school, and the instructor gave them rules on how to do a bibliography, the rules for Wikipedia was that citations had to include the date and time of the version they were citing. With this information, anyone, at any point in the future, could go to the “history” tab and look up the version that had been cited.
In contrast, EB doesn’t have citations at all.
My memory (if faulty, someone will please correct me) is that at the end of an EB article, you will find the initials of the author, and then you can go i-forget-where to find the name of the author and his credentials. But that still doesn’t tell you where he got his information, so you eitherr trust him or you don’t. There’s no way to see his sources, which is possible (at least sometimes) on Wikipedia.
From everything I’ve read, it’s pretty low. Didn’t the EB basically go bankrupt, or has changed business models several times to try and compete with the Internet and Wikipedia? That pretty much tells you strong it’s value proposition is.
But will the content be good forever?
My fifth grade science book (this’d be… 1992-ish) has a section titled
Note the question mark.
Clearly, my school had got its money’s worth out of those books, but is that necessarily a good thing?
Not just on political topics; anyone with a high-stakes agenda (read: money, usually) attracts this kind of manipulation. Check out the discussion page on the notorious con artist Kevin Trudeau.
In Wikipedia, everything will be true for fifteen minutes.