Textbook: 

Svinicki, M., and McKeachie, W.J. (2010). McKeachie's Teaching Tips: Strategies, Research, and Theory for College and University Teachers, Belmont, CA: Wadsworth Publishing, 13th edition.

Chapter 3: "Meeting a class for the first time: assessing prior knowledge." p. 26. 

DePaul Teaching Commons.  (2007-2011).  Identifying Students' Prior Knowledge.  http://teachingcommons.depaul.edu/Classroom_Activities/priorknowledge.html

Eberly Center for Teaching Excellence.  Carnegie Mellon University. (n.d.)  Explore Potential Strategies.  http://www.cmu.edu/teaching/solveproblem/strat-backgroundknowledge/backgroundknowledge-04.html

EnglishClub.com.  (no date)  Teaching Multi-Level Classes - http://www.englishclub.com/teaching-tips/teaching-multi-level-classes.htm  Website.