**John Fox** is professor of sociology at McMaster University in Hamilton, Ontario, Canada. Fox earned a PhD in sociology from the University of Michigan in 1972, and prior to arriving at McMaster, he taught at the University of Alberta and at York University in Toronto, where he was cross-appointed in the sociology and mathematics and statistics departments and directed the university's statistical consulting service. He has delivered numerous lectures and workshops on statistical topics in North and South America, Europe, and Asia, at such places as the summer program of the Inter-University Consortium for Political and Social Research, the Oxford University Spring School in Quantitative Methods for Social Research, and the annual meetings of the American Sociological Association. Much of his recent work has been on formulating methods for visualizing complex statistical models and on developing software in the R statistical computing environment. He is the author and co-author of many articles, in such journals as *Sociological Methodology*, *Sociological Methods and Research*, *The Journal of the American Statistical Association*, *The Journal of Statistical Software*, *The Journal of Computational and Graphical Statistics*, *Statistical Science*, *Social Psychology Quarterly*, *The Canadian Review of Sociology and Anthropology*, and *The Canadian Journal of Sociology*. He* *has written a number of other books, including *Regression Diagnostics* (SAGE,* *1991), *Nonparametric Simple Regression* (SAGE, 2000), *Multiple and General-**ized Nonparametric Regression* (SAGE, 2000), *A Mathematical Primer for Social Statistics *(SAGE, 2008), and, with Sanford Weisberg, *An R Companion to Applied Regression, Second Edition* (SAGE, 2010). Fox also edits the SAGE* *Quantitative Applications in the Social Sciences (QASS) monograph series.