Dr. Michael P. Cohen is a Principal Sampling Statistician in the Education Statistics Program at the American Institutes for Research (AIR). He has over 40 years’ experience in complex survey design and estimation, including sample design, imputation, variances, sample size and power determination, and weighting. Dr. Cohen is a Certified Professional Statistician. He is a Fellow of AAAS, the American Statistical Association, AERA, and RSS. He is an ISI Elected Member.