I believe that both Wikipedia and Stack Exchange are reliable sources for quick access to our specific problems, that we are looking for. But my only concern is Wikipedia seems to be editable by anyone (may be by non-expert). On other hand, Stack Exchange seems to be controlled by experts in the concerned areas. Is there any worth comparison of the two?
Stack Exchange and Wikipedia are both crowd-sourced sites. Experts and non-experts alike can post content to both. Some Stack Exchange answers link to Wikipedia, and some Wikipedia articles link to Stack Exchange answers. It is highly probable that there's overlap between the Wikipedia editors who edit the articles on mathematics and the users who answer questions on Mathematics Stack Exchange. And maths is sufficiently uncontroversial that neither has a major problem with trolls deliberately posting incorrect statements. Both will have some errors, because to err is human; quantifying the error rates would be a major project, but I think they're both low enough that you shouldn't worry.
The main advantages of Wikipedia over Stack Exchange are:
- There's no space constraint. An article can go into as much depth as the editor desires.
- The structure as an encyclopaedia allows (indeed, encourages) lots of cross-referencing.
The main advantages of Stack Exchange over Wikipedia are:
- The structure as Q&A allows (indeed, encourages) multiple answers, which approach the subject from different points of view without any expectation that they form a unified whole.
- The voting works fairly well as a way of separating correct and incorrect answers; and comments about apparent errors are on the same page rather than hidden on a Talk: page.
- It's personalised. Wikipedia addresses principles, but won't give you help with specific examples which you can't understand.