Comparing stochastic design decision belief models : pointwise versus interval probabilities.

Decision support systems can either directly support a product designer or support an agent operating within a multi-agent system (MAS). Stochastic based decision support systems require an underlying belief model that encodes domain knowledge. The underlying supporting belief model has traditionally been a probability distribution function (PDF) which uses pointwise probabilities for all possible outcomes. This can present a challenge during the knowledge elicitation process. To overcome this, it is proposed to test the performance of a credal set belief model. Credal sets (sometimes also referred to as p-boxes) use interval probabilities rather than pointwise probabilities and therefore are more easier to elicit from domain experts. The PDF and credal set belief models are compared using a design domain MAS which is able to learn, and thereby refine, the belief model based on its experience. The outcome of the experiment illustrates that there is no significant difference between the PDF based and credal set based belief models in the performance of the MAS

Mutual Knowledge of Rationality in the Electronic Mail Game

This paper reexamines the paradoxical aspect of the electronic mail game (Rubinstein, 1989). The electronic mail game is a coordination game with payoff uncertainty. At a Bayesian Nash equilibrium of the game, players cannot achieve the desired coordination of actions even when a high order of mutual knowledge of payoff functions obtains. We want to make explicit the role of knowledge about rationality of players, not only that of payoff functions. For this purpose, we use an extended version of the belief system model developed by Aumann and Brandenburger (1995). We propose a certain way of embedding the electronic mail game in an belief system. And we show that for rational players to coordinate their actions, for any embedding belief systems, it is necessary that the upper bound order of mutual knowledge of payoff functions exceeds the upper bound order of mutual knowledge of rationality. This result implies that under common knowledge of rationality, the coordination never occurs, which is similar to Rubinstein's result. We point out, however, that there exists a class embedding belief systems for which the above condition is also sufficient for the desired coordination.

INTERSUBJECTIVE CONSISTENCY OF BELIEFS AND THE LOGIC OF COMMON BELIEF

We characterize the class of n-person belief systems for which common belief has the properties of the strongest logic of belief, KD45. The characterizing condition states that individuals are not too mistaken in their beliefs about common beliefs. It is shown to be considerably weaker than the consistency condition on interpersonal beliefs implied by the common knowledge assumption: it allows individuals to ""agree to disagree"" and to be quite incorrect about others7 beliefs.

Hierarchies of knowledge: ethnobotanical knowledge, practices and beliefs of the Vhavenda in South Africa for biodiversity conservation

Indigenous and local knowledge systems are characterised by a ‘knowledge-practice-belief’ complex that plays a critical role for biodiversity management and conservation on indigenous lands. However, few studies take into consideration the interconnected relationship between the social processes underpinning knowledge accumulation, generation and transmission. The study draws on ethnobotanical research to explore plant uses, practices and belief systems developed among the indigenous Vhavenda in South Africa for sustaining indigenous plant resources and highlights some of the forces of change influencing the acquisition and transmission of knowledge