How Do Individuals Think About Knowledge and Knowing?

In everyday encounters with new information, conflicting ideas, and claims made by others, one has to decide who and what to believe. Can one trust what scientists say? What’s the best source of information? These are questions that involve thinking and reasoning about knowledge, or what psychologists call “epistemic cognition.” In Chapter 5, “How Do Individuals Think About Knowledge and Knowing?,” the authors explain how public misunderstanding of scientific claims can often be linked to misconceptions about the scientific enterprise itself. Drawing on their own research and that of others, the authors explain how individuals’ thinking about knowledge influences their science doubt, resistance, and denial. They explain how educators and communicators can enhance public understanding of science by emphasizing how scientific knowledge is created and evaluated and why it should be valued.

Common Knowledge in an Epistemic Logic with Hypotheses

We extend epistemic logic S5r for reasoning about knowledge under hypotheses with distributive knowledge operator. This extension gives possibility to express distributive knowledge of agents with different background assumptions. The logic is important in com- puter science since it models agents behavior which already have some equipped knowledge. Extension with distributive knowledge shows to be extremely interesting since knowledge of an arbitrary agent whose epistemic capacity corresponds to any system between S4 and S5 under some restrictions can be modeled as distributive knowledge of agents with cer- tain background knowledge. We present an axiomatization of the logic and prove Kripke completeness and decidability results.

Completeness by Modal Definitions. Application to the Epistemic Logic With Hypotheses

We investigate the variant of epistemic logic S5 for reasoning about knowledge under hypotheses. The logic is equipped with a modal operator of necessity that can be parameterized with a hypothesis representing background assumptions. The modal operator can be described as relative necessity and the resulting logic turns out to be a variant of Chellas’ Conditional Logic. We present an axiomatization of the logic and its extension with the common knowledge operator and distributed knowledge operator. We show that the logics are decidable, complete w.r.t. Kripke as well as topological structures. The topological completeness results are obtained by utilizing the Alexandroff connection between preorders and Alexandroff spaces.

Common Knowledge in Epistemic Logic With Hypotheses

We recall the epistemic logic S5r for reasoning about knowledge under hypotheses and we investigate the extension of the logic with an operator for common knowledge. The logic S5r is equipped with a modal operator of necessity that can be parameterized with hypotheses representing background assumptions while the extension with the common knowledge operator enables us to describe and reason about common knowledge among agents with possibly different background assumptions. We present an axiomatization of the logic and prove Kripke completeness and decidability results.

On Limited Conjunctions and Partial Features in Parameter-Tractable Feature Logics

Standard reasoning problems are complete for EXPTIME in common feature-based description logics—ones in which all roles are restricted to being functions. We show how to control conjunctions on left-hand-sides of subsumptions and use this restriction to develop a parameter-tractable algorithm for reasoning about knowledge base consistency. We then show how the resulting logic can simulate partial features, and present algorithms for efficient query answering in that setting.

An Epistemic Event Calculus for ASP-based Reasoning About Knowledge of the Past, Present and Future

We present a generalisation of the Event Calculus, specified in classical logic and implemented in ASP, that facilitates reasoning about non-binary-valued fluents in domains with non-deterministic, triggered, concurrent, and possibly conflicting actions. We show via a case study how this framework may be used as a basis for a "possible-worlds" style approach to epistemic and causal reasoning in a narrative setting. In this framework an agent may gain knowledge about both fluent values and action occurrences through sensing actions, lose knowledge via non-deterministic actions, and represent plans that include conditional actions whose conditions may be initially unknown.

Reasoning about knowledge and messages in asynchronous multi-agent systems

We propose a variant of public announcement logic for asynchronous systems. To capture asynchrony, we introduce two different modal operators for sending and receiving messages. The natural approach to defining the semantics leads to a circular definition, but we describe two restricted cases in which we solve this problem. The first case requires the Kripke model representing the initial epistemic situation to be a finite tree, and the second one only allows announcements from the existential fragment. After establishing some validities, we study the model checking problem and the satisfiability problem in cases where the semantics is well-defined, and we provide several complexity results.

Strategically knowing how

In this paper, we propose a single-agent logic of goal-directed knowing how extending the standard epistemic logic of knowing that with a new knowing how operator. The semantics of the new operator is based on the idea that knowing how to achieve phi means that there exists a (uniform) strategy such that the agent knows that it can make sure phi. We give an intuitive axiomatisation of our logic and prove the soundness, completeness, and decidability of the logic. The crucial axioms relating knowing that and knowing how illustrate our understanding of knowing how in this setting. This logic can be used in representing and reasoning about knowledge-how.