Tamara Denning William G. Griswold Beth Simon Michelle Wilkerson Multimodal communication in the classroom: what does it mean for us? 219-223 2006 conf/sigcse/2006 SIGCSE http://doi.acm.org/10.1145/1121341.1121410 db/conf/sigcse/sigcse2006.html#DenningGSW06