LIRa Session: Gaia Belardinelli

Speaker: Gaia Belardinelli (University of Copenhagen)

Date and Time: Thursday, June 23rd 2022, 16:30-18:00, Amsterdam time.

Venue: online.

Title: The dark side of knowledge: modeling implicit cognition in unawareness structures.

Abstract. There are different notions of implicit knowledge in psychology, sociology, philosophy, logic, computer science, etc. A common feature is that they refer to knowledge that lies in some “dark” (non-explicit) level of awareness. Unawareness structures by Heifetz et al. (2006, 2008) are event-based models featuring a complete lattice of state-spaces. The spaces are used to represent different awareness levels, which makes these structures naturally suited to represent various implicit knowledge notions. Yet, so far, unawareness structures only include a notion of explicit knowledge. In this talk, we first show how to define implicit knowledge à la Fagin-Halpern (1988) in unawareness structures, by deriving it from explicit knowledge. Second, we use a notion of awareness bisimulation contraction, based on awareness bisimulation by van Ditmarsch et al. (2018), to construct an unawareness structure from a Fagin-Halpern ’88 awareness model (and vice versa), and prove their formula equivalence with respect to a language for implicit and explicit knowledge and awareness. Third, we extend unawareness structures to include a notion of tacit knowledge à la Polanyi (1962, 1966), and point at future directions of this project, such as how to empirically identify and thus reveal an agent’s tacit knowledge from her actions, or how to weaken the strong S5 notion of implicit knowledge to capture more descriptive phenomena such as implicit biases. This is joint work with Burkhard C. Schipper.