Andy Peytchev is a senior survey methodologist at RTI International. His research interests include study designs that minimize total survey error and is particularly interested in the study, reduction, and adjustment of nonresponse and measurement error. Dr. Peytchev’s recent work includes the evaluation of split questionnaire design, multi-frame and multi-phase study design, development of adaptive and responsive survey designs, augmentation of survey samples with external data and evaluation of their properties, improving weighting adjustments, and imputation for unit nonresponse and measurement error.