Stuart H. Mann

An examination of the effectiveness of multi-dimensional decision-making methods: a decision-making paradox

Abstract This paper presents the results of a study that compared four decision-making methods. The methods examined were the weighted sum model, the weighted product model, the analytic hierarchy process, and the revised analytic hierarchy process. Two evaluative criteria were used in an attempt to find the best method. The first criterion was to see if the method when accurate in a multi-dimensional situation remained accurate in a single-dimension case. The second criterion determined the stability of a method in yielding the same outcome when a nonoptimal alternative was replaced with a worse alternative. Tests were conducted using simulated decision problems where random numbers were used for the values of the many combinations of alternatives and criteria. The results illustrate the paradox of deciding on a single best decision-making method. While this paradox is not resolved, useful information is presented for comparing the four methods tested.

Attitudes and Conditions for Cooperation in a Paper Recycling Program

Receptivity toward paper recycling was examined in relation to peoples accuracy with wastepaper separation among: (1) personnel with two wastebaskets in offices, (2) personnel with divided wastebaskets, (3) personnel depositing nonsalvageable waste outside offices. A large university was used for the research, and half of each study group received encouragement to cooperate throughout this experiment. Findings indicated that receptivity and accuracy in wastepaper separation were related positively, but separation was better where the required effort was minimal, as in offices with two wastebaskets. Peoples accuracy with wastepaper separation deteriorated over time, but not enough to nullify the effect of asking people to participate in a paper recycling program. Encouragement did not have a statistically significant impact on accuracy with separation. Finally, no change in receptivity toward manual wastepaper separation was found among participants after the experiment. Therefore, the investigators concluded that office workers are willing and able to cooperate in paper recycling, though more needs to be known about improving peoples accuracy in manual wastepaper separation.

An evaluation of the eigenvalue approach for determining the membership values in fuzzy sets

Abstract The membership values of the elements of a fuzzy set of key importance in any theoretical or practical application of fuzzy set theory. Although there are many methods that evaluate membership values, the methd proposed by Saaty [8,9] based on matrix of pairwise comparisons and eigenvalue theory, is the backbone of many other methods. In this paper we evaluate the above method by using a forward error analysis approach with the assumption that the true membership values in a fuzzy set are continuous in the interval (0, 1). The results reveal that the eigenvalue method is dramatically inaccurate even for fuzzy sets with few members.

Minimization approach to membership evaluation in fuzzy sets and error analysis

Evaluation of the degree of membership in fuzzy sets is a fundamental topic in fuzzy set theory. Saaty (Ref. 1) proposes a method for solving this problem that has been widely accepted. In this paper, we examine the problem from an error minimization point of view that attempts to reflect the real intentions of the decision maker. When this approach is used, the findings reveal that fuzzy sets of different cardinalities have dramatically different requirements in the consistency level of the input data as far as the error minimization criterion is concerned.

A computational evaluation of the original and revised analytic hierarchy process

Abstract The Analytic Hierarchy Process (AHP) and its variants have long been used in numerous scientific and engineering applications. The present paper demonstrates that the original AHP and one of its variants have the potential to reach the wrong conclusion under certain circumstances. This paper examines the effectiveness of these two methods under the assumption that in reality the pairwise comparisons, which are used in these methods, take on continuous values. This assumption is made in order to capture the majority of the real world cases. The computational results in this paper demonstrate that when the above assumption is made, the AHP and the revised AHP might yield a different ranking of the alternatives than the ranking that would result if the actual relative importances were known. The same results also reveal a dramatic increase in the probability that an incorrect ranking occurs as the number of alternatives involved increases.

The Hospitality Classroom, Circa 2005

This article traces the history of information technology in education, reviews the current uses of information technology, and projects what hospitality classrooms might look like in 2005. The discussion is extended to the implications for training in the hospitality industry. To achieve the forecasted changes, the view of education must shift from training to performance and from documentation to the application of knowledge.

The Problem of Determining Membership Values in Fuzzy Sets in Real World Situations

One of the fundamental concepts in fuzzy set theory is the one of membership values. An appealing procedure for deriving information about membership values, is to use a matrix of pairwise comparisons [18], [19], [20]. A number of OR approaches that are based on eigenvalue theory and mathematical programming have been proposed to manipulate the previous matrices and estimate membership values. The findings of this paper reveal that although some methods appear to be more effective than others, still their performance is dramatically poor.

A social indicator based on time allocation

The authors have developed a social indicator, called Lambda, that has as its base the manner in which individuals allocate their time among various life activities. This indicator does not suffer from the usual demand characteristics and experimenter bias associated with most subjective social indicators, i.e., those based on question-naires. It is not a single rate indicator in the sense of suicide rate. Lambda is a weighted sum social indicator with both subjective and objective aspects. The weights are decided by the population under consideration and not by the investigators or some other outside agents. The elements to be summed are the frequency functions for the discrepancies that arise when individuals state the amount of time they would like to spend in an activitiy versus the amount of time they actually spend at the activity. There are frequency functions for each activity. The properties of this indicator are discussed in detail.A pilot study comparing Lambda to another social indicator and some demographic variables was conducted with 1012 undergraduate students. The results of the pilot study show a high correlation between Lambda and the other social indicator. The results are presented. Lambda is currently being used by the Gallup organization.

On the Optimal Size for Exploited Natural Animal Populations

This paper considers natural animal populations whose members are harvested for their own value, either esthetic or monetary. At the time of the harvest, population members are assumed to be indistinguishable as to sex. Revenue and cost structures are defined for these populations as they relate to the ecosystem. A stochastic description of population growth is used in which a change in the distribution of the growth parameter is described by an associated Markovian distribution process. This associated process describes the changes in environmental conditions. A harvesting policy is described in terms of an optimal population size. This policy maximizes the expected economic gain to be realized for the duration of time over which management of the system is anticipated.

Sociological Aspects of Waste Paper Recovery

Environmental managers in the business of designing solid waste management systems have a great need for sociological information about those who discard waste. This paper summarizes the literature on attitudinal and behavioral aspects of waste paper recovery, specifically looking for conditions under which attitudes and behavior were congruent. Attitudebehavior congruence is a pertinent sociological concern for the environmental manager, because conservation-oriented attitudes do not necessarily lead to conservation-oriented behavior. Only one study was uncovered about waste paper recovery where the relationship between attitudes and behavior was directly observed; it suggested that anti-litter attitudes and behavior were consistent. Other research has suggested hypothetical conditions which may contribute to a high congruence between attitudes and behavior. These conditions include personal cost, knowledge, and adequate storage space for separated categories of waste paper. Studies on behavioral prompting and reinforcement of waste paper recovery have indicated that without individual or group incentives, conservation-oriented behavior is relatively unlikely to be prevalent in American society, regardless of attitudes toward this kind of activity.