... question,random choice can be performed to improve the cov-erage to 100%. Thus, for each knowledge resource wecompared cases without/with random choice, whichare denoted “w/o Random” and “w/ Random” ... related to how and why, so as to enhance Web-based natural language understanding.AcknowledgmentsThe authors would like to thank NOVA, Inc. for theirsupport with the Nova dictionary and Katunobu ... entries to esti-mate P (t|c) and P (t), which are relative frequenciesof t in c and all the domains, respectively. We usedthe ChaSen morphological analyzer (Matsumoto et al.,1997) to extract...