On this episode, Dr. Mary Ellen Dello Stritto is joined by Dr. Kathleen Preston, an Associate Professor in the Department of Psychology at California State University, Fullerton. Dr. Preston teaches several statistics courses including introductory, advanced, and multivariate statistics, as well as psychometrics, and structural equation modeling. She earned her Ph.D. in 2011 in quantitative psychology from UCLA. Her research interests are in using Item Response Theory, specifically the nominal response model, to develop and refine psychological measurement tools. Dr. Preston is co-director of the Fullerton Longitudinal Study where she applies advanced statistical techniques to long-term longitudinal data. Dr. Preston is considered an expert in statistical analysis using R programming and she has recently published a textbook on analyzing multivariate statistics using R. She has given numerous invited statistical presentations and workshops at national and regional conferences, universities, and federal government agencies. Segment 1: Psychometrics and Item Response Theory [00:00-20:11] In this first segment, Kathleen discusses psychometrics, and how she got interested in quantitative psychology; she explains item response theory and the nominal response model and their applications. In this segment, the following resources are mentioned: Item Response Theory Nominal Response Model Segment 2: Analysis of the Fullerton Longitudinal Study [20:12 -37:44] In segment two, Kathleen discusses the Fullerton Longitudinal Study, the benefits and drawbacks of the study and the statistical methods she employs in her research. In this segment the following resources are mentioned: Fullerton Longitudinal Study Some of Kathleen's publications on the nominal response model and the Fullerton Longitudinal Study: Preston, K., Parral, S., Gottfried, A.W, Oliver, P., Gottfried, A. E., Ibrahim, S. & Delany, D. (2015). Applying the Nominal Response Model Within a Longitudinal Framework to Construct the Positive Family Relationships Scale. Educational and Psychological Measurement, 75, 901-930. Preston, K. S. J., Gottfried, A. W., Park, J. J., Manapat, P. D., Gottfried, A. E., & Oliver, P. H. (2018). Simultaneous Linking of Cross-Informant and Longitudinal Data Involving Positive Family Relationships. Educational and Psychological Measurement, 78(3), 409–429. To share feedback about this podcast episode, ask questions that could be featured in a future episode, or to share research-related resources, post a comment below or contact the “Research in Action” podcast: Twitter: @RIA_podcast or #RIA_podcast Email: riapodcast@oregonstate.edu Voicemail: 541-737-1111 If you listen to the podcast via iTunes, please consider leaving us a review. The views expressed by guests on the Research in Action podcast do not necessarily represent the views of Oregon State University Ecampus or Oregon State University.