Symposia and Workshops
More symposia may be announced later.

Symposium: Symposium in honor of Bill Batchelder
Host: Zita Oravecz (Penn State University)

The central theme of this symposium will be the many contributions made by William H. Batchelder (1940-2018). Bathelder was a leader in the field of mathematical psychology whose pioneering work includes contributions to mathematical psychology, psychometrics, and cognitive science, but also anthropology, sociology, and other social and behavioral sciences. He was one of the first to recognize the power of combining mathematical cognitive modeling with psychometrics and measurement, and much of his later work focused on the hybrid discipline he coined Cognitive Psychometrics. The symposium will feature research talks by students and collaborators of Batchelder’s, as well as presentations of novel research project that follow in one of the paths he began.

Symposium: Recent Developments in Modeling Strategy Use in Searching and Deciding
Host: Michael D. Lee (UC Irvine), Kevin Gluck (AFRL)

This symposium explores some emerging new ideas in theory, models, and methods for understanding how people use strategies to search for information and make decisions. In terms of theory, we are interested in questions like the stability of strategy use, individual differences, and decision making in dynamic and social environments. Is strategy use related to other psychological properties of individuals? Do people switch strategies and, if they do, how often, why, and when do they they switch? How does strategy use change in various social settings, or in response to different individual or group goals? In terms of models, we are interested in strategies beyond the set usually considered in the literature. Interesting probabilistic variants on classic strategies like take-the-best and the weighted-additive rule have recently been proposed, and extensions of the tally heuristic like tally-N raise modeling challenges. Methodologically, there has been a recent burst of activity using Bayesian latent-mixture models and information theory measures like Normalized Maximum Likelihood to make inferences about strategy use from behavioral data. Overall, we hope to share recent achievements and raise new challenges for the diverse set of cognitive modelers who all work on understanding the complexity underlying the way people make decisions.

Symposium: Organizational Principles of Vision
Hosts: Zygmunt Pizlo (UC Irvine), Jun Zhang (University of Michigan)

Symmetry has played a fundamental role in physics ever since Emmy Noether (1918) connected symmetry with conservation laws operating under the dynamics that obeys a least-action principle. These concepts have been used both in classical and modern physics to explain the Natural Laws. Symmetry has also manifested in the Erlanger Program (1872) which arranged several geometries into a single hierarchy, from topology, to projective, affine and Euclidean geometry. This session will explore how symmetry and group invariants can be used in providing explanations of visual perception of 3D space and objects within it. Invariants are obviously relevant in theories of perceptual constancies and redundancy inherent in symmetry is instrumental in solving the inverse problem of reconstructing 3D space and recovering 3D objects by applying a priori intuitive physics to the projected 2D images. This session may also shed light on how higher cognition may be bootstrapped from a cognitive architecture of constrained optimization based on operations and representation constructed from vision.

Workshop: Version Control with Git
Host: Daniel Stubbs (Calcul Québec)

Version control is the lab notebook of the digital world: it’s what professionals use to keep track of what they’ve done and to collaborate with other people. Every large software development project relies on it, and most programmers use it for their small jobs as well. And it isn’t just for software: books, papers, small data sets, and anything that changes over time or needs to be shared can and should be stored in a version control system. This is a 3.5h course at a beginner level. Experience with shell commands is useful, but not mandatory. The lesson plan includes these topics: “Automated Version Control”, “Setting Up Git”, “Creating a Repository”, “Tracking Changes”, “Exploring History”, “Ignoring Things”, “Remotes in GitHub”, “Collaborating”, “Conflicts”, and “Open Science, licensing and hosting.”

Workshop: Professional Development Symposium
Host: Women of Math Psych

Workshop: The Twenty-Sixth Annual ACT-R Workshop
Host: Christian Lebiere

Details available at