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Formal Methods for the Informal World
Mark Dechesne, Larissa Koupriouchina, Leiden University – Campus The
This will be an overview over formalization as a philosophical method, with particular emphasis on its use in ethics. Some of the topics to be covered are: Why do we formalize? How does formalization in philosophy relate to formalization (mathematization) in other disciplines? Why do we mostly use logic, and what advantages and disadvantages does it have in relation to other formal languages? Is the usefulness of logic limited to issues concerning the validity of arguments? Can non-truth-functional concepts such as values be adequately represented in logic? A large part of the presentation will focus on various pitfalls in logical representation.
Emiliano Lorini, IRITA logic for reasoning about moral agents
The aim of this work is to provide a logical analysis of moral agency. Although this concept has been extensively studied in moral philosophy and in economics, it has been far less studied in the areas of logics of agents and multi-agent systems. We discuss different aspects of moral agency such as the distinction between desires and moral values and the concept of moral choice. All these concepts are formalized in a logic of actions and agents' mental attitudes including knowledge, desires, moral values and preferences.
Paul Ormerod, Volterra Partners, London
‘Does quality matter? ‘Rational’ agent behaviour in the 21st century’
In social network markets, the act of consumer choice in these industries is governed not just by the set of incentives described by conventional consumer demand theory, but by the choices of others in which an individual’s payoff is an explicit function of the actions of others.
We observe two key empirical features of outcomes in such markets. First, a highly right-skewed, non-Gaussian distribution of the number of times competing alternatives are selected at a point in time. Second, there is turnover in the rankings of popularity over time.
Such outcomes can arise either when there is no alternative which exhibits inherent superiority in its attributes, or when agents find it very difficult to discern any differences in quality amongst the alternatives which are available so that it is as if no superiority exists. These features appear to obtain, as a reasonable approximation, in many social network markets.
There is an extensive literature developing formal models of rational belief change with contributions from logicians, computer scientists, game theorists and philosophers. Many of the recent developments in this area have been offered on the basis of analyses of concrete examples. These range from toy examples---such as the infamous muddy children puzzle, the Monty Hall problem, and the Judy Benjamin problem---to everyday examples of social interaction. Different frameworks are then judged, in part, on how well they conform to the analyst’s intuitions about the perceived relevant set of examples. This raises an important issue: Implicit assumptions about what the agents know and believe about the situation being modeled often guide the analyst’s intuitions. In many cases, it is crucial to make these underlying assumptions explicit. In this talk, I will examine a purported counterexample to a postulate of iterated belief revision. The suggestion is that the example is better seen as a failure to apply the theory of belief revision in sufficient detail. Although this talk is aimed at the literature on the philosophical foundations of the AGM theory of belief revision, I will raise a number of issues that apply to any formal model of social situations. The general message is that it is often unclear whether a specific example is a “genuine” counterexample to an abstract theory or a misapplication of that theory to a concrete case.
In the presentation I will present a formalism of the problem of many hands. This is a problem that arises whenever a collective is responsible for some undesirable outcome but none of its memebers can be held reasonably responsible for the outcome. For a proper formalisation of responsibilities several “ingredients” are needed, such as agents’ actions, abilities, obligations and knowledge. Earlier works often do not deal with all of these ingredients.
The formalism proposed - Coalition Epistemic Dynamic Logic (CEDL) - is a logic that extends the propositional dynamic logic. In CEDL actions are ‘enacted’ by groups of agents, and operators are added to express agents’ knowledge. The main contribution of the formalism is twofold. The first is the notion of distributed knowledge to generalise the definition of knowledge, ability, and responsibility to groups of agents. With the second, the notion of organisation structure, we can formalise organised groups of agents. In particular, we can formalise information en delegation actions. All together this enables us to model the problem of many hands in organisations, and to show how organised groups of agents are more likely to avoid such problem.
Exploring if Rich Socio-Cognitive Models Enhance the Realism of Virtual Agent Societies.
I hypothesize that using richly detailed socio-cognitive (Heavy) agent models supported by ethno-political-economic data sets to profile the important State and Sub-State Actors will enhance and improve analyses & forecasting with (light) virtual society models. After explaining the heavy and light agent based models and some tools to help generate them, this talk examines several case studies where this approach was applied to model actual regions around the world. I will conclude with lessons learned about the respective pros and cons of each of the heavy and light agent components.
Scientific thinking reveals formal structures behind ordinary things, generating an experience of stability and beauty. But the connection is often less than clear, and in this talk I will discuss some of my own experiences. My first example is natural language and the opposition of linguistic surface form and underlying logical form that supports valid laws of reasoning. What are logical semantics supposed to reveal, or explain, and against what kinds of facts do we measure their success? My second example is modal logics of informational activities and games, asking similar questions, and making connections with cognitive science.
On the basis of these examples, I will look at a few general themes: doing justice to the facts versus satisfying competing academic communities, dynamic zooming in and zooming out in logical analysis, and the formation of new research lines and even behavior in between logic and human practice.
Ref. Johan van Benthem, 1991, "Language in Action", Elsevier, Amsterdam, 2011, "Logical Dynamics of Information and Interaction", Cambridge University Press, 2008, 'Logic and Reasoning, Do the Facts Matter?', Studia Logica 88, 67-84. http://staff.science.uva.nl/~johan