1. No teacher should accept any citation from Wikipedia, Yahoo Answers, etc. Spend 15 minutes and compile a list of forbidden sites, with options to add to the list if the site appears to be just as problematic. Tell students that not only will such citations not count toward a citation / bibliography quota, but that facts sourced to them will be disregarded when determining the completeness of research.
2. I fully agree we should be teaching kids good source evaluation techniques. Indeed, if those kids in (1) above go to the Wikipedia footnote and drill through to and cite that article, they should be free and clear to navigate. Wikipedia is a great springboard for information (and, for non-academic purposes, a quite decent place to go for info in areas that are non-controversial).
I'll note, though, this is nothing new. Back in my day, the struggle was with kids simply looking up things in encyclopedias. Teens aren't going to exhibit any more "research curiosity" than they absolutely have to; that's not Wikipedia's fault, it's human development. And even if, online, they avoid information crowdsourcing / aggregation sites, they still need to be taught what good citation material looks like — TinFoilHatBob.com is going to have some interesting contributions to make to Suzie's paper about Israel, for example.
Students Citing Wikipedia Could Kill Startups
Students can turn to user-generated search engines for many answers—but not all.
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One of the first things I learned about research was to consider the reliability of the source. For most of my papers, I needed sources that were as unbiased as possible. That eliminates a good chunk of the Web.
And I can recall looking through multiple books from the library, and spotting ones that were outliers in their historical info / interpretation. So bearing in mind bias is useful in any sort of research, not just in context of using Wikipedia.
Wikipedia would be great to get George W. Bush's birthdate, or an outline of major events of his presidency. But anything interpretive would bear major drilling down in sources to look for as primary material as possible.
I maintain an old prof's position on the matter: Wikipedia makes a great gateway for good research material, but to be credible, you always want to go back to the original documents and citations.
She found a case where an education paper from decades ago was being cited, and false attributions made. The paper everyone was referring to was from the same author, a few years earlier. Not a glaring mistake, per se, except that this went completely unchecked, through numerous professional publications, for over 20 years.
http://minkhollow.ca/beckerblog/2012/12/01/dont-beleive-everything-you-read-really-stop-it/
Shortcuts aren't just human development; they're human nature.