Information concerning SIR/PHD methods. Main source: Work of Professor Ker-Chau Li of UCLA His webpage: web.stat.ucla.edu/~kcli/ Information useful: (1) His preprint of a book (more than 250 pages) on the topic "High dimensional data analysis via the SIR/PHD approach" (Under lecture notes in progress, a pdf file) (2) His publication list on the topic. Reading of papers by K.C. Li: 1. "Sliced inverse regression for dimension reduction", with discussions Journal of the American Statistical Association (1991), 86, 316-342. 2. On principal Hessian directions for data visualization and dimension reduction: another application of Stein's lemma. Journal of the American Statistical Association (1992), 87, 1025-1039. Information on recent development: 1. "An adpative estimation of dimension reduction space" with discussions by Xia, Y.m Tong, H., Li, W.K., and Zhu, L.X. Journal of the Royal Statistical Society, Series B, (2002), 64, 363-410. 2. "A goodness-of-fit test for single-index models" with discussion by Xia, Y., Li, W.K., Tong, H., and Zhang, D. Statistica Sinica (2004), 1-39.