Title: Psychometrics in R: A Roundtrip through Latent and Not-so-Latent Variables Author: Patrick Mair Affiliation: Harvard University Abstract: From a methodological point of view it is pretty exciting to work in the field of psychology at the moment. Over the last few years, the advent of new technologies such as eye-tracking and hand motion devices, and especially fMRI (functional magnetic resonance imaging) scanners, have completely changed the way statistical data analysis is done in psychology. The field seems to have shifted from classical latent variable models towards a much broader psychometric methods portfolio. This includes machine learning approaches in fMRI, Bayesian cognitive modeling, all sorts of mixed-effects models, special functional methodology for analyzing eye-tracking and hand motion experiments, as well as old-school latent variable models. How well does R accommodate the needs of modern psychological research? The first part of the talk takes the audience back to the early/mid 2000s when the first psychometric packages were implemented and some initiatives were started in order to boost psychometric developments in R (JSS special issue, Psychometrics Task View on CRAN). Since these early developments there has been a tremendous increase in psychometric package submissions developed by a vital psychometric computing community. Thus, the second part provides an overview of the most important package developments, discusses the status quo of psychometric computing and, more generally, the current role of R in psychology. The third part sets the stage for future developments, since there are still several gaps in the psychometric R package ecosystem that need to be filled.