Carol B. MacKnight, “Teaching Critical Thinking through Online Discussions.” EDUCAUSE Quarterly, 2000, no. 4: 38-41
This article contains some useful pointers on using threaded discussion forums to teach critical thinking skills in online courses. Include in the article is a list of Socratic questions.
The article is available here: http://er.educause.edu/~/media/files/article-downloads/eqm0048.pdf
Or, here: eqm0048