A fifth grade teacher from White bear Lake, Minnesota, Susan Sedro is looking at wikis versus blogs for different purposes, and comparing PBWiki & wikispaces. There are three criteria for this wiki project: readable to families and other schoolclasses, protected from spam but still aloowing comments from outsiders, and trackback of changes, who did what (and eventually find a malicious editor).
Wikispaces announced not long ago that for k-12 education wikis will be free of ads, and could be private for others than the users - with no charge (usually you need to pay a small fee for this service. But one problem may be that students do nto have an email , as they need to get individual invitationf to be able to contribute and edit the blog.Adventures in Educational Blogging: Which Wiki? or The Trouble Without Email