Research examined information combination in both choice and pre-choice (screening) phases of decision making. Three experiments required subjects to review a set of multiattributed options for a possible purchase. Each option had either high or low expected probability of availability, and a set number of positive or negative attributes. In the first experiment, subjects were asked to indicate their preferred choices. Analysis showed that the majority of subjects multiplicatively combined the probability of option availability with other option attributes, as predicted by expected utility theory. In the second experiment, subjects were asked to eliminate unacceptable options, but not choose. Analysis showed that the majority of subjects additively combined information on negative option attributes (violations) with low probability of option availability, as predicted by image theory. The third experiment showed that when choice immediately followed screening, 28% of the subjects used multiplicative information combination to make the choice, 28% used additive combination, and both types of combination were equally dominant in the remaining 44% of the subjects.

Emotionality in environmental decisions is a function of the characteristics of the environmental planning problem, the decider, and of the situation in which decisions occur. This research examined the effects of problem and decider characteristics upon the emotionality of the decision process and upon decisions. Descriptions of a resource management problem were varied in a two by four factorial design with two writing style levels (emotional and objective) and differential emphasis of two pro-development and two pro-preservative issues. Subjects read a problem description, made and evaluated confidence in a decision, placed the decision on a 156 mm preservation-development continuum, rated their emotionality on 42 scale items, and completed an Environmental Attitude Survey. Data analysis indicated that pro-development issue emphases resulted in more development decisions and lower confidence than pro-preservation emphases. Also, negative affect, environmental concern, preservation decisions, and confidence were interrelated. Neither independent variable affected emotionality, however, possibly due to the effects of the order of experimental instruments on salience of emotional response. A second experiment was conducted with half the original problem descriptions. Emotions were made more salient by asking subjects to complete the emotion scale instrument before making or describing their decisions. Significantly more preservation decisions were made in this second experiment and confidence in decisions increased. Increased negative affect was found in the second experiment also. Three major conclusions were reached. First, emotionality is a significant predictor of environmental decisions. The weakness of its predictive power may be due to the verbal, hypothetical, experimental setting. Second, the configuration of preservation decisions, high confidence, and negative affect could be related to behavior such as environmental activism, and bears further empirical investigation. Third, environmental decisions may be highly variable and sensitive to differences in situations and informational variables. A multi-method approach to study of environmental decisions and to gathering of public input is advocated.

This dissertation describes three different hierarchical schemes for routing and flow control in communication networks. The basic idea in these schemes is to distribute the decision making capability among different hierarchical levels. A part of the decision is made at the lower level of network nodes and another part is made at the higher level of Coordinators. Specific problems at the lower level of nodes and the higher level of Coordinators are formulated in an optimization framework and solutions to these problems result in the overall control scheme. Two modes of operation for the Coordinators are identified and a step by step procedure to implement these modes of operation is also developed. Performance evaluations of these hierarchical schemes are conducted using stochastic models and simulation experiments. Different models for the nodes are used while developing these hierarchical schemes. In one of these schemes a queueing model is used to design a buffer allocation scheme to implement flow control while in another a state dependent model is used to design a combined routing and flow control scheme. The solution to this combined problem is obtained through the concepts of system stabilization. Major strong points of these hierarchical schemes are as follows. They provide a framework for integrating routing and flow control functions. They provide consideration of multiple objectives such as delay, throughput, and fairness individually. By implementing the Coordinators action at a slower time scale, the trade-off existing in information overheads and optimality can be exploited.

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