Dr. Alexandru Cernat is a lecturer in Social Statistics at the University of Manchester. Previously he was a Research Associate at the National Centre for Research Methods, University of Manchester, where he investigated non-response in longitudinal studies with a special focus on biomarker data. He has received a Ph.D. in survey methodology from the University of Essex working on the topic of mixed-mode designs in longitudinal studies. His research interests are in latent variable modeling, longitudinal data, measurement error, missing data and new forms of data.