A Second Opinion: An Expert System for Data Analysis
Leland Wilkinson
Computer Science, University of Illinois at Chicago, Chicago, IL, United States; Systat Software Inc., Chicago, IL, United States

Statistical expert systems were the focus of several research programs more than a decade ago, but commercial and open-source statistics packages have generally failed to take advantage of the findings from that research. A Second Opinion is an attempt to combine an expert statistical system with a new graphical user interface to provide users with a second opinion on data analyses they have already performed with a conventional statistical package. The expert system includes extensive testing for anomalies, diagnostics of model residuals, and remedial recommendations. Diagnostics are based on a combination of robust statistical estimates, nonparametric tests, and classic tests of assumptions. The user interface takes advantage of contemporary developments in interaction technology. This interface – tested on both novice and expert users – has no keyboard input, user manual, or dialog boxes. All interaction is designed for a mouse or touch-screen interface. The output is a browser-based document with exportable graphics, technical explanations and references, and links to Web statistical resources.

Keywords: Expert system; Graphics; Web-based analytics

Biography: Leland Wilkson is Executive VP at Systat Software Inc. and Adjunct Professor of Computer Science at the University of Illinois at Chicago. He wrote the SYSTAT statistical package and founded SYSTAT Inc. in 1984. Wilkinson is a Fellow of the American Statistical Association, a Fellow of the American Association for the Advancement of Science, and an elected member of the International Statistical Institute. In addition to journal articles and the original SYSTAT computer program and manuals, Wilkinson is the co-author of Desktop Data Analysis with SYSTAT and author of The Grammar of Graphics.