Sanford Weisberg is Professor of Statistics at the University of Minnesota, Twin Cities. He is also director of the University's Statistical Consulting Service for Liberal Arts, and has worked with literally hundreds of social scientists and others on the statistical aspects of their research. Professor Weisberg earned a BA in Statistics from the University of California, Berkeley, and a Ph.D. also in statistics from Harvard University, under the direction of Frederick Mosteller. The author of more than sixty articles, his research has primarily been in the areas of regression analysis, includ...