@Inproceedings{chi2008understanding, author = {Chi, Ed H. and Mytkowicz, Todd}, title = {Understanding the efficiency of social tagging systems using information theory}, year = {2008}, number = {}, url = {http://portal.acm.org/citation.cfm?id=1379110&coll=GUIDE&dl=GUIDE&CFID=37458772&CFTOKEN=13998061&ret=1}, doi = {10.1145/1379092.1379110}, const = {\ text} }