Susan Embretson, Georgia Institute of Technology, Atlanta, Georgia, USA
Susan E. Embretson is Professor of Psychology at the Georgia Institute of Technology. Previously she was Professor of Psychology at University of Kansas and Director of the Quantitative Psychology Program there when she moved to Georgia Tech in 2004. She has served as President of the Psychometric Society (1999), the Society of Multivariate Psychology (1998) and American Psychological Association, Division of Measurement, Evaluation and Statistics (1991). She has received several awards for her research on interfacing cognitive psychology with psychometric models including the Saul Sells Award for Distinguished Multivariate Research (Society for Multivariate Experimental Psychology, 2019), Career Contribution Award (National Council on Measurement in Education, 2013), Distinguished Scientific Contribution Award (American Psychological Association, Division of Measurement, Evaluation and Statistics, 2001) and the Technical and Scientific Contribution Award (National Council on Measurement in Education ,1994-1996). Her current research interests include explanatory item response theory models, automatic item generation and dynamic measurement.
Modeling Cognitive Processes, Skills and Strategies in Item Responses: Implications for Test and Item Design
Interpretations of test scores typically involves the assumption that examinees are applying the same cognitive processes, skills and strategies in their item responses. If so, then test scores indicate examinee’s standing on a single latent trait. Results from several studies using mixture and explanatory item response models will be presented to show that this assumption is often not met. The implications of these results for test scoring, interpretations and external correlates, as well as for item and test design will be discussed.
Burr Settles, DuoLingo, Pittsburgh, Pennsylvania, USA
Burr Settles leads the research group at Duolingo, an award-winning website and mobile app offering free language education for the world. He also runs FAWM.ORG, a global annual songwriting experiment. He is the author of Active Learning — a text on machine learning algorithms that are adaptive, curious, and exploratory (if you will). His research has been published in Cognitive Science as well as all the major artificial intelligence venues such as NIPS, ICML, AAAI, ACL, and EMNLP. His work has been covered by The New York Times, Slate, Forbes, WIRED, and the BBC among others. In past lives, Burr was a postdoc at Carnegie Mellon and earned a PhD from UW-Madison. He currently lives in Pittsburgh, where he gets around by bike and plays guitar in the pop band delicious pastries.
Improving Language Learning and Assessment with Data
As scalable learning technologies become more ubiquitous, student data can and should be analyzed to develop new instructional technologies, such as personalized practice schedules and data-driven assessments. I will describe a few projects at Duolingo — the world's largest language education platform with more than 200 million students worldwide — where we combine learner data with machine learning, computational linguistics, and psychometrics to improve learning, testing, and engagement outcomes.
Eric-Jan Wagenmakers, University of Amsterdam, Amsterdam, Netherlands
Eric-Jan Wagenmakers is a mathematical psychologist and a dedicated Bayesian. He works for the Psychological Methods unit at the University of Amsterdam where he coordinates the team that develops JASP, an open-source software program for statistical analyses (www.jasp-stats.org). Wagenmakers is also a strong advocate of open science and the preregistration of analysis plans. For more information see ejwagenmakers.com.
Bayesian Multi-Model Inference for Practical and Impractical Problems
Whenever a set of models is applied to data, uncertainty surrounds both the selection of the best model and the estimation of the model parameters. The coherent Bayesian answer to the model selection question is to avoid all-or-none selection altogether and instead retain model uncertainty, employing it for purposes such as prediction and parameter estimation. Advantages of this multi-model approach include a reduction of overconfidence, improved predictive performance, and an increased robustness against model misspecification. Moreover, the multi-model framework can be seamlessly integrated with the recent open-science ideals of multi-team inference and multiverse analyses. We debunk several philosophical objections to Bayesian multi-model inference and demonstrate its practical use for problems ranging from the simple to the complex.
Dylan Molenaar, University of Amsterdam, Netherlands
Early Career Award
Dylan Molenaar is an assistant professor at the University of Amsterdam, The Netherlands. He obtained his PhD in 2012 from the same university. His dissertation, entitled “Testing distributional assumptions in psychometric measurement models” and supervised by Conor Dolan, received the Dissertation Prize by the Psychometric Society in 2013. In 2014, he was a visiting scholar at the Ohio State University. His current research is funded by a personal grant from the Netherlands Organization for Scientific Research and focusses on psychometric models for responses and response times. Other research interests include factor analysis and item response theory in general, and modeling of intelligence and personality test data.
Beyond simple main effects:
Challenges to the substantive interpretation of higher-order statistical effects
Using traditional psychometric models like the linear factor model and the two-parameter logistic item response theory model, the simple main effects of items and subjects can be inferred from the first two moments of the matrix of observed scores. The resulting parameters are statistically useful for various practical issues including item calibration, test equating, and adaptive testing, and for various substantive issues like establishing group differences in IQ and personality. However, some substantive hypotheses predict statistical effects that go beyond the first two moments of the data. Examples of these higher-order effects include non-linear effects, non-normal effects, heteroscedastic effects, and mixtures of different effects. Studying phenomena like these is substantively interesting but statistically challenging as the distributional assumptions underlying common psychometric models may distort the modeling results once violated. In this presentation, the challenges of studying higher-order statistical effects are illustrated using cases from the fields of intelligence, personality, and response time research.
Merijn Mestdagh, University of Leuven, Belgium
During his master mathematical engineering at the University of Leuven, Merijn Mestdagh specialized in machine learning, statistics and computer sciences. Subsequently, he prepared a PhD at the University of Leuven under the supervision of Francis Tuerlinckx and Stijn Verdonck. During his PhD, he applied the insights of machine learning to substantive research of emotions, aiming to facilitate and improve the mathematical study of affect, which resulted in publications in Nature Human Behavior, Scientific Reports and Psychological Methods.
Prepaid parameter estimation without likelihoods
In various scientific fields, statistical models of interest are analytically intractable and inference is usually performed using a simulation-based method. However elegant these methods are, they are often painstakingly slow and convergence is difficult to assess. As a result, statistical inference is greatly hampered by computational constraints. However, for a given statistical model, different users, even with different data, are likely to perform similar computations. Computations done by one user are potentially useful for other users with different data sets. In this presentation, I recommend a pooling of resources across researchers to capitalize on this. More specifically, I propose to preemptively chart out the entire space of possible model outcomes in a prepaid database. Using advanced interpolation techniques, any individual estimation problem can now be solved on the spot. I will discuss prepaid databases created for several challenging models and demonstrate how they can be distributed through an online parameter estimation service. This method outperforms state-of-the-art estimation techniques in both speed (up to a 100,000-fold speed up) and accuracy, and is able to handle previously quasi inestimable models. Specifically I will demonstrate how this online parameter estimation technique is able to quasi instantaneously estimate the parameters of choice reaction time models without a tractable likelihood.
Francis Tuerlinckx, University of Leuven, Belgium
President of the Psychometric Society 2018-2019
Francis Tuerlinckx is a full professor of quantitative psychology at the University of Leuven (Belgium). He received his PhD in 2000 (under the supervision of Paul De Boeck). His research interests include psychometrics, mathematical modeling of cognition and emotions, and dynamical modeling of time series. A crucial aspect of his research is building bridges between formal models and substantive psychological research questions. Francis Tuerlinckx’s work has been published in Psychometrika, Psychological Bulletin, Psychological Review, Journal of Mathematical Psychology, and Psychonomic Bulletin & Review. Francis Tuerlinckx is an Associate Editor of Journal of Mathematical Psychology.