The problem with the Britannica or other bound source re science is that new data are constantly coming forward. Yearbooks help, but even so, it is hard for the editors to keep up, even with good editors. The yearbooks are helpful, but few ever read them and few subscribed for more than 3-4 years. My Britannicas date from 1940s and 1911 and I have an 1885 Chambers', but I use them mainly for historical perspective. I make an attempt to keep up with a few journals, esp. Science and Nature, but I have to make a trip across town to the library.

Lack of editing, documentation bibliographic information are the pitfalls of Wackipedia. Some articles are good, but others are horribly bad. It may be an easy 'first' place to look, but it should never be the only one checked out.