Associate Professor of Statistics
Ph.D., Cornell University, 1968

Summary of research interests

Dr. Ryan's area of research is statistical computing. He is interested in problems in statistics in which computing issues are a significant part of the solution. An interesting computing question is to find an efficient algorithm. For example, a recently published algorithm for fitting unimodal functions takes over three hours on a fast PC for a sample size of 1,000, while an algorithm Dr. Ryan developed (with two other members of the department) takes only about one second.

Another interesting computing problem is to find the solution of a nonlinear regression problem or other nonlinear problems; available methods for these are not as satisfactory as the methods available for linear models. A third problem is to join existing methods together with new ones to make a complete set of tools for exploring various classes of problems.

Dr. Ryan's graduate training was in mathematical probability. After coming to Penn State, he did some work in applied probability before switching to statistical computing and applied statistics. He was the lead developer of the Minitab package, first developing the system within the department, and from 1983 to 1988 was president of Minitab, Inc. In 1988, he left Minitab, Inc., to return to the department. He is a Fellow of the American Statistical Association.

Representative publications

R. E. Kelly, T. A. Ryan, Jr., and T. P. Hettmansperger. 1990. Fitting unimodal functions I: consistency. Penn State Statistics Department Technical Report No. 85.

T. A. Ryan, Jr. 1990. Analyzing the one-way layout with medians. Proceedings of the Statistical Computing Section, American Statistical Association.

T.A. Ryan, Jr., R. E. Kelly, and T. P. Hettmansperger. 1990. Fitting unimodal functions II: algorithms. Penn State Statistics Department Technical Report No. 84.

T. A. Ryan, Jr., et al. 1988. Minitab reference manual. Minitab, Inc.

Last updated: April 13, 2003