Then the saliency of w in D(T) is defined as −log(hgs(N, K, n, k)) ２ .
sAL(D(T), s) is the number of distinct words in D(T) whose saliency of occurrence is not less than s. For instance, using the 1996 archive of Nihon Keizai shimbun (a Japanese financial newspaper), sAL(D("Aum ３ "), 110) = 74, sAL(D("Aum"), 200) = 50, sAL(D*("do"), 110) = 1, and sAL(D*("do"), 200) = 0, where D*("do") is a set of N 0 randomly chosen articles from D("do") and N 0 is the threshold value stated in subsection 1.2.