关于CiteSpace中的信息熵

Information entropies of the literature of terrorism research between 1990 and the firsthalf of 2007. The two steep increases correspond to the Oklahoma City bombingin 1995 and the September 11 terrorist attacks in 2001. Entropies are computed retrospectivelybased on the accumulated vocabulary throughout the entire period. Twoconsecutive and steep increases of entropy are prominently revealed,corresponding to 1995-1997 and 2001-2003. The eminent increases of uncertaintysend a strong message that the overall landscape of terrorism research musthave been fundamentally altered. The unique advantage of theinformation-theoretic insight is that it identifies emergent macroscopicproperties without overwhelming analysts with a large amount of microscopicdetails. Using the terminology of information foraging, these two periods havetransmitted the strongest information scent. Note that using the numbers ofunique keywords fails to detect the first period identified by informationentropy. Subsequent analysis at microscopic levels reveals that the two periodsare associated with the Oklahoma City bombing in 1995 and the September 11terrorist attacks in 2001.