just sharing, since we are collecting case studies. but this is an example of a perfect case study: (mathias shared this with us)
http://elearningtech.blogspot.com/2007/06/fourth-grader-wikipedia-update.htm...
I just wanted to relate something that I think shows the power of a Wiki in general and Wikipedia particularly.
My son, in 4th grade here in California, was assigned a research report on the California Gold Rush and decided to focus his report on the different routes taken by the 49ers. He used a variety of different resources and particularly used the California Gold Rush Historic Maps from the David Rumsey Map Collection. There is one map in particular that has an incredible description written in 1849 of the different routes: Map of the Gold Regions of California, Showing the Routes via Chagres and Panama, Cape Horn, &c. If you are into maps, this is a fun one to drill down on to see the description.
Of course, my son read the Wikipedia California Gold Rush page (it comes up first in Google). It had a paragraph on the routes, but it didn't include the route through Mexico. It did point us to a detailed article on the California Trail. Because it was rather limited about the routes, my son added a sentence about the route through Mexico and added the Map to the Wikimedia Commons and added the map to the article and added a link to the collection of maps on the topic.
Now 4th graders doing the same project will be able to find that same wonderful primary source.
It's actually somewhat rare that a 4th grader has a primary source like the map, so it's quite a nice little legacy to leave behind. Actually, I don't remember having anything as cool as that to study when I was in school. It's quite remarkable when I think about it.
And it shows the beauty of a Wiki and Wikipedia.