Professor and Chair of Statistics

Ph.D. in Statistics, University of North Carolina at Chapel Hill, 1985

Personal Website

Research Interests

• Applied and computational statistics
• Biostatistics
• Semi-parametric statistical methods
• Multivariate data analysis
• Ordinal and censored data

Honors and Appointments

• Fellow, Institute of Mathematical Statistics (1998)
• Fellow, American Statistical Association (2000)
• Associate Editor, J. Amer. Statistical Society (1996-1999)
• Associate Editor, Chemometrics and Intelligent Laboratory Systems (1999-2006)
• Associate Editor, Biometrics (2000-2006)
• Director, Illinois Statistics Office (1995-2000)
• Chair, Department of Statistics (2000-)

Selected Publications

• Chen, H.-S., Simpson, D.G. and Ying, Z. (2000). Infill asymptotics for a stochastic process model with measurement error. Statistica Sinica, 10, 141-156.
• Xie, M., Simpson, D.G. and Carroll, R.J. (2000). Random effects in interval-censored ordinal regression: latent structure and Bayesian approach. Biometrics, 56, 376-383.
• Simpson, D.G., Imrey, P., Geling, O. and Butkus, S. (2000). Statistical estimation of child abuse rates from administrative databases. Children and Youth Services Review, 22, 951-971.
• He, X., Simpson, D.G. and Wang, G. (2000). Breakdown points of t-type regression estimators. Biometrika, 87, 675-687.
• Zhou, H., Xie, M., Simpson, D.G. and Weinberg, C.R. (2001). A generalized likelihood ratio approach for cluster-correlated data from human fertility studies. Sankhya, Series B, Vol. 63, pp. 56-68.
• Simpson, D.G. (2001). Ordinal response. In: Encyclopedia of Environmetrics. Wiley, New York.
• Imrey, P.B. and Simpson, D.G. (2001). Categorical data. In: Encyclopedia of Environmetrics. Wiley, New York.
• Fu, L. and Simpson, D.G. (2002). Conditional risk models for ordinal response data: Simultaneous logistic regression analysis and generalized score tests. Journal of Statistical Planning and Inference. 108, 201-217. Invited for Volume II in honor of C.R. Rao.
• O’Brien, W.D., Simpson, D.G., Ho, M., Miller, R.J., Frizzell, L.A. and Zachary, J.F. (2003). Superthreshold behavior and threshold estimation of ultrasound-induced lung hemorrhage in pigs: Role of pig age dependency. IEEE Transactions on Ultrasound, Ferroelectrics, and Frequency Control. 50, 153-169.
• He, X., Cui, H. and Simpson, D.G. (2004). Longitudinal data analysis using t-type regression. Journal of Statistical Planning and Inference. Invited for volume in honor of J.W. Tukey. 122, 253-269.
• Kim, T.Y., Kim, D., Park, B.U. and Simpson, D.G.(2004). Nonparametric detection of correlated errors. Biometrika. 91, 491-496.
• Simpson, D.G., Ho, M., Yang, Y., Zhou, J., Zachary, J.F. and O’Brien, W.D. (2004). Excess Risk Thresholds in Ultrasound Safety Studies: Statistical Methods for Data on Occurrence and Size of Lesions. Ultrasound in Medicine and Biology. Vol. 30, pp. 1289-1295.
• O’Brien, W.D., Yang, Y., Simpson. D.G., Frizzell, L.A., Miller, R.J., Blue, J.P., Zachary, J.F. (2006). Threshold estimates of ultrasound-induced lung hemorrhage in adult rabbits, and comparison of thresholds in mice, rats, rabbits and pigs. Ultrasound in Medicine and Biology. Vol 32, pp.1793-1804.