Rense Lange Juan Moran Warren R. Greiff Lisa Ferro A Probabilistic Rasch Analysis of Question Answering Evaluations. 65-72 2004 HLT-NAACL http://acl.ldc.upenn.edu/hlt-naacl2004/main/pdf/114_Paper.pdf db/conf/naacl/naacl2004.html#LangeMGF04