Spatial and conjoint models based on pairwise comparisons of dissimilarities and combined effects: Complete and incomplete designs

In pairwise multidimensional scaling, a spatial representation for a set of objects is determined from comparisons of the dissimilarity of any two objects drawn from the set to the dissimilarity of other pairs of objects drawn from that set. In pairwise conjoint scaling, comparisons among the joint effects produced by pairs of objects, where the objects in a pair are drawn from separate sets, are used to determine numerical representations for the objects in each set. Monte Carlo simulations of both pairwise dissimilarities and pairwise conjoint effects show that Johnson's algorithm can provide good metric recovery in the presence of high levels of error even when only a small percentage of the complete set of pairwise comparisons are tested.     

Axiomatic and numerical conjoint measurement: An evaluation of diagnostic efficacy

Synthetic data are used to examine how well axiomatic and numerical conjoint measurement methods, individually and comparatively, recover simple polynomial generators in three dimensions. The study illustrates extensions of numerical conjoint measurement (NCM) to identify and model distributive and dual-distributive, in addition to the usual additive, data structures. It was found that while minimum STRESS was the criterion of fit, another statistic, predictive capability, provided a better diagnosis of the known generating model. That NCM methods were able to better identify generating models conflicts with Krantz and Tversky's assertion that, in general, the direct axiom tests provide a more powerful diagnostic test between alternative composition rules than does evaluation of numerical correspondence. For all methods, dual-distributive models are most difficult to recover, while consistent with past studies, the additive model is the most robust of the fitted models.Douglas Emery is now at the Krannert Graduate School of Management, Purdue University, West Lafayette, IN, on leave from the University of Calgary.     

The use of teachers as behavioral observers

The effect of using teachers as behavioral observers on both student and teacher behavior was examined with eight teachers and 32 elementary school children. The frequency of prompts (but not praise or criticism) to those students observed by the teacher increased significantly from nonobserver to teacher observed experimental phases. In addition, students observed by the teacher showed more change in appropriate behavior than students who were not observed. The significance of these findings for research and therapy is discussed.     

Considerations in the choice of interobserver reliability estimates

Two types of interobserver reliability values may be needed in treatment studies in which observers constitute the primary data-acquisition system: trial reliability and the reliability of the composite unit or score which is subsequently analyzed, e.g., daily or weekly session totals. Two approaches to determining interobserver reliability are described: percentage agreement and "correlational" measures of reliability. The interpretation of these estimates, factors affecting their magnitude, and the advantages and limitations of each approach are presented.     

INTERACTIONS BETWEEN TEACHER GUIDANCE AND CONTINGENT ACCESS TO PLAY IN DEVELOPING PREACADEMIC SKILLS OF DEVIANT PRESCHOOL CHILDREN1

Token-mediated access to play and snacks was made contingent on completion of academic tasks in the Baseline Experiment. This contingency produced stable completion rates that were subsequently doubled, and then tripled, for four deviant children in a special preschool. A reversal design demonstrated that the contingency was functional in maintaining the children's rates of task completion. The Guidance Experiment examined the role of a social event, teacher guidance, in the acquisition of task-completion skills, in a multiple-baseline-across-tasks design (with reversals). The analysis demonstrated that teacher guidance was an important supplement to the token-mediated contingency in establishing significant increases in task completions for a second group of three deviant children in the special class. The importance of teacher guidance was related to the difficulty level of the children's tasks.     

Correlation and prediction in ordinal test theory

Based on the test theory model for ordinal measurements proposed by Schulman and Haden, the present paper considers correlations between tests, attenuation, regressions involving true and observed scores, and prediction of test reliability.The population correlation between tests is shown to be related to the expected sample correlation for samples of sizen ₁ andn ₂. Errors of estimation, measurement and prediction are found to be similar to their counterparts in interval test theory, while attenuation is identical to its counterpart. The bias in estimating population reliability from sample data is compared for Kendall's tau and Spearman's rho.The author wishes to thank the referees for their helpful comments on an earlier draft of this paper, and in particular, for the suggested alternative methods of establishing some of the presented results.     

矛盾年龄偏见量表在中国大学生群体中的修订及信效度检验

目的：修订矛盾年龄偏见量表(the Ambivalent Ageism Scale, AAS),并在中国大学生群体中进行信、效度检验。方法：对1182名大学生施测AAS中文翻译版,探索并验证其因子结构,分析信、效度和测量等值性。其中347人还完成老化知识量表(FAQ)和容纳他人量表(AOS),用以检验AAS中文版的校标关联效度。另有74人在4周后重测AAS中文版。结果：AAS中文修订版包含认知帮助/保护、不想要的帮助和敌意年龄偏见三因子,总量表和各维度的Cronbach’s α系数依次为0.83、0.80、0.85、0.76,重测信度依次为0.78、0.62、0.78、0.71。AAS中文修订版及各维度与FAQ和AOS负相关(r=-0.23～-0.48,ps<0.001)。验证因素分析表明AAS中文修订版的拟合良好(χ²/df=3.51,CFI=0.96,TLI=0.94,RMSEA=0.07,SRMR=0.05)。且该量表跨性别形态、弱等值、部分强等值和部分严格测量等值成立。结论：修订后的矛盾年龄偏见量表(AAS)中文版的信、效度良好,具备跨性别的测量部分...     

Selecting a new technology strategy using multiattribute,multilevel decision trees

Research indicates that selecting a strategy to best exploit a new technology is a complex decision-making process. The task involves making a series of decisions with multiple alternatives, each to be evaluated by multiple criteria whose values have high levels of uncertainty. This paper presents a methodology for modelling a new technology decision using decision trees and an optimizing algorithm. A problem of a mining company considering the adoption of new technology is used to illustrate the decision-making task and modelling methodology. A numerical solution to the case demonstrates the potential of the optimizing technique in strategy selection.