ion Modulation In many cases, it may be more useful to do normative inference on a model that is deemed to be complete at a particular level of abstraction than it is to do an approximate or heuristic analysis of a model that is too large to be analyzed under specific resource constraints. It may prove useful in many cases to store several belief-network representations, each containing propositions at different levels of abstraction. In many domains, models at higher levels of abstraction are more tractable. As the time available for computation decreases, network modules of increasing abstraction can be employed. ffl Local Reformulation Local reformulation is the modification of specific troublesome topologies in a belief network. Approximation methods and heuristics designed to modify the microstructure of belief networks will undoubtedly be useful in the tractable solution of large uncertain-reasoning problems. Such strategies might be best applied at knowledge-encoding time. An...

Advancing the state of the art of simulation in the social sciences requires appreciating the unique value of simulation as a third way of doing science, in contrast to both induction and deduction. This essay offers advice for doing simulation research, focusing on the programming of a simulation model, analyzing the results and sharing the results with others. Replicating other people’s simulations gets special emphasis, with examples of the procedures and difficulties involved in the process of replication. Finally, suggestions are offered for building of a community of social scientists who do simulation.

ly on the accuracy of the prediction; errors in predicting feelings are measured in units of divorce, dropout, career burnout and consumer dissatisfaction. The accuracy of people's predictions of their own feelings is important not only for individual well-being but, increasingly, also for public policy. Recent decades have seen an expansion of 1 attempts to base public policies on measurements of public values. The best-known of such efforts is Oregon's experiment in health-care rationing, but attempts to base public policy on public values have been made in diverse areas, such as transportation safety and environmental policy Measurement of public values typically involves surveys in which respondents are asked 2 to predict how they would feel if they were in health conditions or environmental states different from the ones they are in. The meaningfulness of the measured values, and the optimality of the policies based on them, therefore, depend, in

In this paper we propose an extension to the traditional model of bounded rationality and incorporate the extended model into a theory of organizational behavior. We argue that organizations are collections of tasks and intelligent agents engaged in performing those tasks, both situated within an organizational setting. Organizational behavior is an emergent property of such collections and is constrained by the agent, the task, and the situation. We propose that a unified theory of organizational behavior is possible, but only if agents, tasks, and situations are specified at a sufficient level of detail, and only if that specification embodies both the agents' mental models of the task and social-situation and the task and social-situation. Inattention to relevant details of the agent, task, or situation (and their interactions) may produce misleading results. We describe a candidate theory, ACTS theory, that integrates Agents who are Cognitively-restricted, Task-oriented, and Socially-situated in an interlinked set of representational systems. We suggest that the complexity of the theory warrants its realization and testing in a computational form, and that there exist candidate computational theories of cognitive agents and organizational situations. We illustrate the importance of attending to task

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This paper describes research-in-progress that examines the relative influences of internal and external factors on the development and use of intranets, as a particular case of information and communication technologies (ICTs). This threephase qualitative study integrates cross-sectional, comparative and traversal methodologies to identify where it could be effective to combine sociotechnical theory (emphasizing individuals and social groups) with institutional approaches (emphasizing interaction through influence and regulation.) Preliminary results suggest that a balance of pressures are at work, with external factors motivating the use of intranets and other forms of web information systems within the constraints of

Planning and the user interface: the effects of lockout time and error recovery cost

Managers must choose to allocate scarce resources either to the maintenance of a range of products tailored to heterogeneous consumer preferences or to the efficient production of a small number of products. In addition, managers must choose the degree to which they periodically cull the product line. Vigorous selection removes poor performers from the product line, but this action simultaneously impairs the firm’s ability to monitor changes in consumer preferences. Empirical evidence from the computer workstation industry reveals that the ideal choice of product variety depends on the competitive ecology of the industry. Product variety becomes less valuable as the total number of products on the market increases, but it increases in value as uncertainty makes the accurate prediction of demand difficult. How many variations on a product should a company produce? Henry Ford once remarked that customers could choose his Model T in any color “so long as it was black. ” Although the color example is extreme, lack of product variety allowed Ford to take dramatic advantage of economies of scale through assembly-line production. Nevertheless, this focus also opened the door for General Motors. By providing consumers with choice, General Motors increased its market share from 10 % in the early 1920s to 45 % in 1940. Product variety can be an important strategic variable. With finite capital, the manager must allocate resources either to creating multiple products tailored to individual consumer preferences or to developing efficient processes to produce a few products (Spence, 1976; Lancaster, 1979; Moorthy, 1984). Multiple product offerings can increase sales (Perloff and Salop, 1985) and allow producers to charge higher prices (Pigou, 1920), but producing a variety of goods can also increase production costs,

Findings from behavioral organization theory, behavioral decision theory, survey research and experimental economics leave no doubt about the failure of rational choice as a descriptive model of human behavior. But this does not mean that people and their politics are irrational. Bounded rationality asserts that decision-makers are intendedly rational; that is, they are goal-oriented and adaptive, but because of human cognitive and emotional architecture, they sometimes fail, occasionally in important decisions. Limits on rational adaptation are of two types: procedural limits, which are limits on how we go about making decisions, and substantive limits, which affect particular choices directly. Rational analysis in institutional contexts can serve as a standard for adaptive, goal-oriented human behavior. In relatively fixed task environments, such as asset markets or elections, we should be able to divide behavior into adaptive, goal-oriented behavior (that is, rational action) and behavior that is a consequence of processing limits, and measure the deviation. The extent of deviation is an empirical issue. These classes are mutually exclusive and exhaustive, and may be examined empirically in situations in

Abstract. The rapid expansion of Decision and Negotiation Support Systems has been built mainly on decision theoretic approaches. This has resulted in the decision maker being viewed through the lens of the problem. In this paper the focus is on the decision maker's view of the problem. Three levels of problem articulation are described. Special emphasis is placed on the needs level and the implications it carries for the cognitive and instrumental levels. The three levels of articulation, the organizational model of making decision in social settings and the three basic approaches to decision making form the basis for computer support focused on understanding and change rather than preferences and outcomes. We argue that in the dynamic, interactive context characteristic of negotiations, a cognitive support system based on restructurable modelling provides a richer basis for support.