Dear all,

Tomorrow we will have two events of interest to the LIRa audience. The first is the DIEP talk of Alexandru Baltag, from 11:00 to 12:30. The second is our LIRa session with Cedegao Zhang, from 15:00 to 16:30 (please note the ***UNUSUAL TIME*** compared to our regular sessions!). You can find the details for both events, as well as their Zoom links, below.

----------------------------------------------------- *DIEP talk*

Date and time: Thursday, June 17th 2021, 11:00-12:30, Amsterdam time.

Speaker: Alexandru Baltag (UvA)

Title: Group (Ir)Rationality: Can Logic help?

Abstract:

I present some applications of logical methods (in particular, of so-called dynamic epistemic logics) to the study of emergent phenomena in groups of `agents\', capable of reflection, communication, reasoning, argumentation etc.The main focus on the understanding of belief/preference formation and diffusion in social networks, and on how this affects the group\'s ``epistemic potential\": the ability of the agents to track the truth of the matter (with respect to some given relevant topic). While in some cases, ``wisdom of the crowds\" can increase the epistemic potential, in other situations the group\'s dynamics leads to informational distortions (-- the ``madness of the crowds\": cascades, ``groupthink\", the curse of the committee, pluralistic ignorance, group polarization, doxastic cycles etc). I explain how logic (in combination with probabilistic methods) can be used to provide some explanations for both types of situations, as well as to suggest some partial solutions to informational distortions.

Zoom link: https://uva-live.zoom.us/j/85608909905

---------------------------------------------------- *LIRa Session*

Speaker: Cedegao Zhang (University of California, Berkeley)

Date and Time: Thursday, June 17th 2021, 15:00-16:30, Amsterdam time.

Title: A Computational Model of Higher-Order Epistemic Reasoning.

Abstract. Reasoning about what other people know is an important cognitive ability, known as epistemic reasoning, which has fascinated psychologists, economists, and logicians. We propose a computational model of humans’ epistemic reasoning, including higher-order epistemic reasoning—reasoning about what one person knows about another person’s knowledge—that we test in an experiment using a deductive card game called “Aces and Eights”. Our starting point is the model of perfect higher-order epistemic reasoners given by the framework of dynamic epistemic logic. We modify this idealized model with bounds on the level of feasible epistemic reasoning and stochastic update of a player’s space of possibilities in response to new information. These modifications are crucial for explaining the variation in human performance across different participants and different games in the experiment. Our results demonstrate how research on epistemic logic and cognitive models can inform each other.

This is a joint work with Ham Huang and Wesley Holliday. A preprint is available at https://psyarxiv.com/7hkzd/.

Zoom link: https://uva-live.zoom.us/j/92907704256?pwd=anY3WkFmQVhLZGhjT2JXMlhjQVl1dz09 (Meeting ID: 929 0770 4256, Passcode: 036024)

Hope to see you there!

The LIRa team