The Subject Wikis Blog

In a blog post elsewhere, I gave my take on the use of online references for mathematics. Three of the most used general websites for English-language mathematics reference are Wikipedia, Planetmath, and Mathworld. In the blog post, I described how I came to discover these individual resources, and how I have come to use Wikipedia more and more for general reference. I also raised the possibility that the diversion of effort into Wikipedia might have been responsible for the slowdown in growth of Mathworld and Planetmath.

An online reference resource that I didn’t mention is Springer Encyclopedia of Mathematics. Unlike the other three resources, the Springer Encyclopedia is largely an online adaptation of a print work of the same name.

I’m curious to know if those among my readers who are students or researchers in mathematics have other general-purpose references than these. Also, readers of academic subjects other than mathematics, what general-purpose references do you use? I’m looking for names of references that give direct dictionary- or encyclopedia-like entries online, as opposed to services that only help in locating journal articles or books.

Beyond that, I’m interested in what people have to say about the following:

• What do you see as the relative strengths and weaknesses of Wikipedia, Mathworld and Planetmath, in terms of the quality of final entries and ease of use? Here, for instance, are the entries on “normal subgroup” on Wikipedia, Mathworld, Planetmath, and Springer. You might also want to contrast them with the entry on the group properties wiki, but the Groupprops entry on normal subgroup isn’t in general very representative of subject wiki entries as of now.

• When looking for information, are you more likely to go directly to a reference site such as Wikipedia, Mathworld, Planetmath, or Springer, and search for the page from within the site, or to search using a general-purpose search engine such as Google?

• What pushes you to use one of these reference sites? If you are near a computer or other web-enabled device, do you prefer to check an online reference site rather than hunt for a definition in a book? For what kind of things do you prefer using books, notes, and journal articles and for what kind of things do you prefer using online reference sites?

• To what extent do you follow links within a reference site once you’ve got there? Do you check out how material is organized with a reference site when you visit it, to make future trips proceed more smoothly?

Looking forward to input on this!