CWilsie

 Both wikis are fairly easy to set up. Both were fairly easy to invite others to join. PBWiki had an option as to have people join in different roles (writer, editor, reader). Wikispaces you just invited them to join and then you could have them be a member or promote them to //organizer.// (advantage equal) //**Your article should explore the way the 2 (or more) of the wiki software handles editing. (Is it WYSIWYG? Does it have templates? Automatic Headings?, comments?)**// Both had visual and code editing. Wikispaces you could customize much more for free (logo, color, template); PBWiki requires you to upgrade to have these features. I was able to upload photos and embed video on both. They each had little differences -- PBWikis had //plug-ins//, which had several options. Wikispaces had //widgets//, with many similar options. One notable difference was wikispaces has a discussions tab per page and PBWiki has a Comment area at the bottom of the page, like a blog (which I think I prefer, but not a big difference). (advantage wikispaces, but it was close -- so many features were FREE on wikispaces that it got the nod) //**Version Control - How is page history handled?**// PBWikis you can see page history from a couple of places: //Recent Activity// on the FrontPage and from //View All Pages.// Wikispaces has a //Recent Changes// link on the side that shows you what has been changed, and then when you click on it it also shows you what was changed by highlighting it.   (advantage wikispaces) //**Discussion - Is there a place to talk about the article outside?**// See above -- I'm not sure what //**outside**// means exactly//**.**// //**Subscription to articles - How can you be notified of changes to the pages you contribute to?**// Both had notification features. PBWiki was sending emails to everyone I invited for every edit I made -- I didn't realize that. So I unclicked those notifications, but now I don't see to how reinstate them if I wanted to. On wikispaces it seems that each member wold need to sign up individually for notifications. (advantage wikispaces) //**Security - How will you be able to control page edits?**// On both you can set it to Public or Private**.** (advantage equal) //**Contributions - How can teachers see what each student has contributed to the wiki?**// See //**Version Control.**// (advantage wikispaces)  Overall, I would have to say I prefer wikispaces over PBWiki. I was annoyed by the having to upgrade on PB to get free stuff on wikispaces. On most things they were more or less equal. Of course, it would be nice to be able to take the things you like from each (and others I'm sure) and create the perfect wiki.
 * //How easy is it to set up? - How easy will it be to invite others?//**

My wikis: http://cwilsie.wikispaces.com/ http://cwilsie.pbwiki.com/