... indicates a latent semantic class of co-occurrence (hidden class) . Probabilistic parame-ters P (n|z), P (r, v|z), and P (z) in Equation (9)can be estimated by using the EM algorithm. Inour ... best parse and next-best parses. While ourreranking model using generation probability isquite simple, we can easily verify our hypothesisthat the two proposed probabilities have an effecton ... r, and verb v)by using probabilistic latent semantic indexing(PLSI) (Hofmann, 1999)5. If n, r, v is theco-occurrence of n and r, v, we can calculateP (n, r, v) by using the following...