A methodology to assess the utility of future space systems

The Air Force SPACECAST 2020 study identified and prioritized some future space systems and technologies required in the next century. This paper presents the results of research on the SPACECAST 2020 value model. The model determines and prioritizes future space systems’ utility towards controlling and exploiting space. This research identifies the assumptions and simplifications in the additive utility function and assesses modifications. The research shows that mutual utility independence of the mission areas is a reasonable assumption. Mutual utility independence allows the use of the multiplicative and multilinear utility functions. Also, the SPACECAST 2020 scoring functions used the same scoring scale and only measured the utility of future capabilities. This study makes modifications to the SPACECAST 2020 measure-of-merit scoring functions. It replaces most of these functions with either a concave, convex, linear or ‘S’ scoring function, which have expanded capability ranges to include both current and future capabilities. The modified scoring functions and alternative utility functions do not alter the SPACECAST 2020 results but do improve the credibility and future usefulness of the model. This study shows that the initial assumption of using an additive utility function is also valid. © 1997 John Wiley & Sons, Ltd.     

The same but different: an empirical investigation of the reducibility principle

According to classical utility theory the valuation of any lottery should depend only on its outcomes and their respective probabilities, and should not be affected by the nature, complexity and structure of the chance mechanism. Previous research has documented systematic violations of this principle. For example, most subjects prefer lotteries in which the payoffs are contingent on the joint occurrence of multiple (high probability) events to simple lotteries, and lotteries in which the earlier stages offer higher probabilities than the later stages. We review the various violations of this principle and suggest a classification into two major types associated with misunderstanding of chance mechanisms and attitude towards the chance mechanism and process. In the present study 40 subjects were presented with 30 pairs of binary gambles. In any given pair the lotteries had identical outcomes and equal ‘reduced’ probabilities (and thus equal expected values). However, the chance mechanisms varied along a variety of factors such as the size of the sample space, the number of stages, temporal ordering, order of probabilities, their transparency and time constraints. Half the subjects saw lotteries involving gains and the other half considered only losses. After choosing one lottery in each pair, the subjects were asked to explain and justify their choices. The findings revealed systematic violations of the reducibility principle: subjects displayed a preference for lotteries with larger sample spaces, and for lotteries that allow quicker resolutions in the earlier stages. A clear distinction between some patterns of preferences in the gains and loss domains was revealed. In gambles involving gains subjects preferred to have the highest probability on the first stage (and the lowest probability on the last stage), but displayed the opposite preferences for losses. A content analysis of the subjects' stated reasons for their choices identified eight major categories. The most frequently invoked were hope, fun, simplicity, stress and time. Copyright © 2001 John Wiley & Sons, Ltd.     

Using Estimates of the Output Productivity Ratio (SDp) to Improve the Accuracy and Managerial Acceptance of Utility Analysis Estimates

This study compared nursing supervisors' percentile estimates (15th, 50th, and 85th) of staff nurse performance made in terms of dollar value and two alternative metrics—output (number of patients cared for) and staffing (number of nurses required to staff a unit). Of the three estimation procedures, nursing supervisors were most confident in the accuracy of their output-based estimates and least confident in the accuracy of their dollar value-based estimates. Estimates of the standard deviation of performance as a percentage of mean performance (SDp) ranged from 19% for the staffing-based estimate to 29% for the output-based estimate. Contrary to expectations, dollar value-based SDp estimates were only minimally correlated with staffing- and output-based SDp estimates. I conclude that allowing supervisors to make percentile estimates in terms of familiar metrics has potential value for improving the accuracy and managerial acceptability of utility analysis.     

Doubly Robust-Type Estimation for Covariate Adjustment in Latent Variable Modeling

Due to the difficulty in achieving a random assignment, a quasi-experimental or observational study design is frequently used in the behavioral and social sciences. If a nonrandom assignment depends on the covariates, multiple group structural equation modeling, that includes the regression function of the dependent variables on the covariates that determine the assignment, can provide reasonable estimates under the condition of correct specification of the regression function. However, it is usually difficult to specify the correct regression function because the dimensions of the dependent variables and covariates are typically large. Therefore, the propensity score adjustment methods have been proposed, since they do not require the specification of the regression function and have been applied to several applied studies. However, these methods produce biased estimates if the assignment mechanism is incorrectly specified. In order to make a more robust inference, it would be more useful to develop an estimation method that integrates the regression approach with the propensity score methodology. In this study we propose a doubly robust-type estimation method for marginal multiple group structural equation modeling. This method provides a consistent estimator if either the regression function or the assignment mechanism is correctly specified. A simulation study indicates that the proposed estimation method is more robust than the existing methods. This research was partially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Young Scientists (B), 187-30406.     

心理因素如何影响风险决策中的价值运算？——兼谈Kahneman的贡献

风险决策是一个复杂的心理过程,由于心理因素的加入,其中的价值运算有不同于经济学与数学的运算规则。价值的心理学界定可以总结为三方面：效用、值函数、心理帐户,三种界定遵循着不同的心理学规律。Kahneman提出的值函数概念具有承先启后,集其大成的作用,它破除了理性神话,显示了价值运算对认知加工的依赖。     

Reference-dependent utility with shifting reference points and incomplete preferences

Many empirical studies have shown that people's preferences are reference-dependent. Previous theoretical studies of reference-dependence assumed that the reference point was fixed and then imposed the usual assumptions of decision theory, in particular completeness of preferences. This paper gives preference foundations for additive reference-dependent utility when the reference point varies across decisions and is one of the options in the decision maker's opportunity set. This decision situation is common, for example because usually the retention of the status quo is an available option, but is difficult to handle axiomatically because it implies incompleteness of preferences. The results of this paper provide tools to extend existing theories of reference-dependent preferences, such as prospect theory, to new and empirically important decision contexts.     

An Interactive Approach for Multicriteria Decision Making Using a Tchebycheff Utility Function Approximation

Multicriteria decision making (MCDM) can provide an efficient mean for considering various and conflicting objectives to reveal the alternative that maximizes the decision maker's (DM) utility. In this paper, we propose a new interactive MCDM method for implicit alternatives to help a DM obtain a most preferred solution. We employ a Tchebycheff function to generate weights for objectives consistent with the DM's responses to pairwise comparisons between alternatives and present a mixed integer linear programming formulation to generate these weights. Thus, we approximate the DM's utility function by a Tchebycheff function and generate weights consistent with the DM's responses. We test our approach with different true utility functions on various sized multiple criteria linear programming problems. The computational results show that even with non‐Tchebycheff true utility functions, our method can generate alternatives very close to the optimal solution with few questions. The comparison of our results with other methods reveals its advantages. Copyright © 2013 John Wiley & Sons, Ltd.     

《周易》古经与墨家思想

诸子之学皆源于《易》。就墨家而言,其思想的基本特征为贵节非乐,贵兼泛爱．尚用尚齐,兴利节用,尚力自苦,尚贤尚同．右鬼薄葬,非礼非命。以此为参照,考诸《易经》,不难发现．墨家思想的许多方面,如尚节、尚力、尚用、兴利等,皆可在《易经》中见其端绪。     

The role of multiple-choice tests in increasing access to difficult-to-retrieve information

Answering multiple-choice questions improves access to otherwise difficult-to-retrieve knowledge tested by those questions. Here, I examine whether multiple-choice questions can also improve accessibility to related knowledge that is not explicitly tested. In two experiments, participants first answered challenging general knowledge (trivia) multiple-choice questions containing competitive incorrect alternatives and then took a final cued-recall test with those previously tested questions and new related questions for which a previously incorrect answer was the correct answer. In Experiment 1, participants correctly answered related questions more often and faster when they had taken a multiple-choice test than when they had not. In Experiment 2, I showed that the more accurate and faster responses were not simply a result of previous exposure to those alternatives. These findings have practical implications for potential benefits of multiple-choice testing and implications for the processes that occur when individuals answer multiple-choice questions.     

Rejoinder: Remaining Challenges in Investigating Grade-Retention Effectiveness

This rejoinder, in response to the commentaries of Steiner, Park, and Kim (this issue) and Reshetnyak, Cham, and Hughes (this issue), discusses remaining challenges in grade retention research. First, a same-age comparison assumes that the instruments used in different grades measure ability equally well. We discuss the importance of evaluating the properties of the scaling process to address whether this assumption has been met. Second, we discuss issues in the selection of covariates to be included in the weights. Third, we discuss the unconfoundedness assumption and the problem of remaining imbalance. Finally, we provide an empirical illustration showing that studying grade-retention effectiveness comes with multiple methodological decisions that are rooted in a bias–variance trade-off.