•  1624
    The goal of the present paper is to construct a formal explication of the pluralistic ignorance explanation of the bystander effect. The social dynamics leading to inaction is presented, decomposed, and modeled using dynamic epistemic logic augmented with ‘transition rules’ able to characterize agent behavior. Three agent types are defined: First Responders who intervene given belief of accident; City Dwellers, capturing ‘apathetic urban residents’ and Hesitators, who observe others when in doub…Read more
  •  409
    Convergence, Continuity and Recurrence in Dynamic Epistemic Logic
    In Alexandru Baltag, Jeremy Seligman & Tomoyuki Yamada (eds.), Logic, Rationality, and Interaction (LORI 2017, Sapporo, Japan), Springer. pp. 108-122. 2017.
    The paper analyzes dynamic epistemic logic from a topological perspective. The main contribution consists of a framework in which dynamic epistemic logic satisfies the requirements for being a topological dynamical system thus interfacing discrete dynamic logics with continuous mappings of dynamical systems. The setting is based on a notion of logical convergence, demonstratively equivalent with convergence in Stone topology. Presented is a flexible, parametrized family of metrics inducing the l…Read more
  •  74
    Infostorms
    Metaphilosophy 44 (3): 301-326. 2013.
    It has become a truism that we live in so-called information societies where new information technologies have made information abundant. At the same time, information science has made us aware of many phenomena tied to the way we process information. This article explores a series of socio-epistemic information phenomena resulting from processes that track truth imperfectly: pluralistic ignorance, informational cascades, and belief polarization. It then couples these phenomena with the hypothes…Read more
  •  32
    In a recent paper, Christian List has argued for the compatibilism of free will and determinism. Drawing on a distinction between physical possibility and agential possibility, List constructs a formal two-level model in which the two concepts are consistent. This paper's first contribution is to show that though List's model is formally consistent, philosophically it falls short of establishing a satisfactory compatibilist position. Ensuingly, an analysis of the shortcomings of the model leads …Read more
  •  25
    Dynamic Epistemic Logics of Diffusion and Prediction in Social Networks
    with Alexandru Baltag, Zoé Christoff, and Sonja Smets
    Studia Logica 107 (3): 489-531. 2019.
    We take a logical approach to threshold models, used to study the diffusion of opinions, new technologies, infections, or behaviors in social networks. Threshold models consist of a network graph of agents connected by a social relationship and a threshold value which regulates the diffusion process. Agents adopt a new behavior/product/opinion when the proportion of their neighbors who have already adopted it meets the threshold. Under this diffusion policy, threshold models develop dynamically …Read more
  •  20
    Intensional Protocols for Dynamic Epistemic Logic
    with Hanna S. van Lee and Suzanne van Wijk
    Journal of Philosophical Logic 48 (6): 1077-1118. 2019.
    In dynamical multi-agent systems, agents are controlled by protocols. In choosing a class of formal protocols, an implicit choice is made concerning the types of agents, actions and dynamics representable. This paper investigates one such choice: An intensional protocol class for agent control in dynamic epistemic logic, called ‘DEL dynamical systems’. After illustrating how such protocols may be used in formalizing and analyzing information dynamics, the types of epistemic temporal models that …Read more
  •  14
    This thesis is on information dynamics modeled using *dynamic epistemic logic*. It takes the simple perspective of identifying models with maps, which under a suitable topology may be analyzed as *topological dynamical systems*. It is composed of an introduction and six papers. The introduction situates DEL in the field of formal epistemology, exemplifies its use and summarizes the main contributions of the papers.Paper I models the information dynamics of the *bystander effect* from social psyc…Read more
  •  13
    Intensional Protocols for Dynamic Epistemic Logic
    with Suzanne Wijk and Hanna Lee
    Journal of Philosophical Logic 48 (6): 1077-1118. 2019.
    In dynamical multi-agent systems, agents are controlled by protocols. In choosing a class of formal protocols, an implicit choice is made concerning the types of agents, actions and dynamics representable. This paper investigates one such choice: An intensional protocol class for agent control in dynamic epistemic logic (DEL), called ‘DEL dynamical systems’. After illustrating how such protocols may be used in formalizing and analyzing information dynamics, the types of epistemic temporal models…Read more
  •  12
    Dynamic term-modal logics for first-order epistemic planning
    with Andrés Occhipinti Liberman and Andreas Achen
    Artificial Intelligence 286 103305. 2020.
  •  10
    When information grows abundant, attention becomes a scarce resource. As a result, agents must plan wisely how to allocate their attention in order to achieve epistemic efficiency. Here, we present a framework for multi-agent epistemic planning with attention, based on Dynamic Epistemic Logic. We identify the framework as a fragment of standard DEL, and consider its plan existence problem. While it is undecidable in the general case, we show that when attention is required for learning, all inst…Read more
  •  9
    The paper introduces a broad family of metrics applicable to finite and countably infinite strings, or, by extension, to formal structures serving as semantics for countable languages. The main focus is on applications to sets of pointed Kripke models, a semantics for modal logics. For the resulting metric spaces, the paper classifies topological properties including which metrics are topologically equivalent, providing sufficient conditions for compactness, characterizing clopen sets and isolat…Read more
  •  7
    We take a logical approach to threshold models, used to study the diffusion of e.g. new technologies or behaviors in social net-works. In short, threshold models consist of a network graph of agents connected by a social relationship and a threshold to adopt a possibly cascading behavior. Agents adopt new behavior when the proportion of their neighbors who have already adopted it meets the threshold. Under this adoption policy, threshold models develop dynamically with a guaranteed fixed point. W…Read more
  •  7
    Preface
    with Margot Colinet and Sophia Katrenko
  •  6
    Erratum to “Dynamic term-modal logics for first-order epistemic planning” [Artif. Intell. 286 (2020) 103305]
    with Andrés Occhipinti Liberman and Andreas Achen
    Artificial Intelligence 323 (C): 103969. 2023.
  •  5
    The European Summer School in Logic, Language and Information is organized every year by the Association for Logic, Language and Information in different sites around Europe. The main focus of ESSLLI is on the interface between linguistics, logic and computation. ESSLLI offers foundational, introductory and advanced courses, as well as workshops, covering a wide variety of topics within the three areas of interest: Language and Computation, Language and Logic, and Logic and Computation. The 16 p…Read more
  •  5
    Hintikka’s Knowledge and Belief in Flux
    In Hans van Ditmarsch & Gabriel Sandu (eds.), Jaakko Hintikka on Knowledge and Game Theoretical Semantics, Springer. pp. 317-337. 2018.
    Hintikka’s Knowledge and Belief from 1962 is considered the seminal treatise on epistemic logic. It provides the nuts and bolts of what is now a flourishing paradigm of significance to philosophy, economics, mathematics and theoretical computer science—in theory as well as practice. And in theory and for practice epistemic logic has been extensively articulated, refined and developed especially with respect to capturing the dynamics of reasoning about knowledge. But although the robust narrative…Read more
  •  3
    Threshold models and their dynamics may be used to model the spread of ‘behaviors’ in social networks. Regarding such from a modal logical perspective, it is shown how standard update mechanisms may be emulated using action models – graphs encoding agents’ decision rules. A small class of action models capturing the possible sets of decision rules suitable for threshold models is identified, and shown to include models characterizing best-response dynamics of both coordination and anti-coordinat…Read more