A graphical method for simplifying Bayesian games

If the influence diagram (ID) depicting a Bayesian game is common knowledge to its players then additional assumptions may allow the players to make use of its embodied irrelevance statements. They can then use these to discover a simpler game which still embodies both their optimal decision policies. However the impact of this result has been rather limited because many common Bayesian games do not exhibit sufficient symmetry to be fully and efficiently represented by an ID. The tree-based chain event graph (CEG) has been developed specifically for such asymmetric problems. By using these graphs rational players can make analogous deductions, assuming the topology of the CEG as common knowledge. In this paper we describe these powerful new techniques and illustrate them through an example modelling a game played between a government department and the provider of a website designed to radicalise vulnerable people

On distinguishing epistemic from pragmatic action

We present data and argument to show that in Tetris-a real-time, interactive video game-certain cognitive and perceptual problems ore more quicktv, easily, and reliably solved by performing actions in the world than by performing com-putational actions in the head atone. We have found that some of the translations and rotations made by players of this video game are best understood as actions that use the world to improve cognition. These actions are not used to implement a plan, or to implement a reaction; they are used to change the world in order to simplify the problem-solving task. Thus, we distinguish pragmatic octions--actions performed to bring one physically closer to a goal-from epistemic actions-actions performed to uncover informatioan that is hidden or hard to compute mentally. To illustrate the need for epistemic actions, we first develop a standard information-processing model of Tetris cognition and show that it cannot explain performance data from human players of the game-even when we relax the assumption of fully sequential processing. Standard models disregard many actions taken by players because they appear unmotivated or superfluous. How-ever, we show that such actions are actually far from superfluous; they play a valuable role in improving human performance. We argue that traditional accounts are limited because they regard action as having o single function: to change the world. By recognizing a second function of action-an epistemic func-tion-we can explain many of the actions that a traditional model cannot. Al-though our argument is supported by numerous examples specifically from Tetris, we outline how the new category of epistemic action can be incorporated into theories of action more generally. In this article, we introduce the general idea of an epistemic action and discuss its role in Tetris, a real-time, interactive video game. Epistemic actions-physical actions that make mental computation easier, faster, or more We thank Steve Haehnichen for his work on the initial implementations of Tetris an

Resource allocation and priority setting in health care: a multi-criteria decision analysis problem of value?

A methodological approach is needed for allocating health care resources in an efficient and fair way that gives legitimacy to decisions. Currently, most priority setting approaches tend to focus on single or limited benefit dimensions, even though the value of new health care interventions is multi-dimensional. Explicit elicitation of social value trade-offs is usually not possible and decision-makers often adopt intuitive or heuristic modes for simplification purposes as part of an ad hoc decision-making process which might diminish the reasonableness and credibility of the decisions. In this paper, we suggest that multi-criteria decision analysis could provide a more comprehensive and transparent approach in health care to systematically capture decision-makers’ concerns, compare value trade-offs and elicit their value preferences. We conclude that such methods could inform the development of a decision support system in health care, contributing towards more efficient, rational and legitimate resource allocation decisions

Arbitration Schemes For Generalized Two-person Games.

PhDMathematicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/179122/2/0003548.pd