Affiliation: | (1) Department of Cognitive Psychology, Carnegie Mellon University, Pittsburgh, PA, 15213;(2) Department of Statistics, University of Washington, Box 354322, Seattle, WA, 98195;(3) AT&T Laboratories, Statistics Research, Murray Hill, NJ, 07974;(4) Information and Computer Science, University of California, Irvine, CA, 92717 |