Two-group classification in latent trait theory: Scores with monotone likelihood ratio

This paper deals with two-group classification when a unidimensional latent trait,, is appropriate for explaining the data,X. It is shown that ifX has monotone likelihood ratio then optimal allocation rules can be based on its magnitude when allocation must be made to one of two groups related to. These groups may relate to probabilistically via a non-decreasing functionp(), or may be defined by all subjects above or below a selected value on.In the case where the data arise from dichotomous items, then only the assumption that the items have nondecreasing item characteristic functions is enough to ensure that the unweighted sum of responses (the number-right score or raw score) possesses this fundamental monotone likelihood ratio property.     

Household hunger,standard of living and satisfaction with life in Alice,South Africa

The objective of this study was to investigate the relationships between household hunger, standard of living and satisfaction with life in a rural South African setting. Respondents were 442 randomly selected community dwellers from Alice, in the Eastern Cape (Xhosa speaking = 89.32%, females = 67%; age range 40–49 years). Multiple regression analysis was utilised to predict satisfaction with life from household hunger and standard of living. Low levels of household hunger, and low to moderate living standards predicted satisfaction with life. Resource support interventions with vulnerable communities should focus on poverty alleviation measures aimed at improving subjective satisfaction levels.     

Magnitudes of score differences produced within sessions in a cooperative exchange procedure

Interest centered on maximal score differences produced within sessions during two-party exchange. Subjects chose between earning money independently or through potentially higher-paying exchange. In the exchange option, only one person could produce points for the other on a trial. Because each exchange response (“give”) required the giver to forego earning points independently, the larger the score difference produced (i.e., the further ahead in earnings the other person was put), the greater the reduction in the giver's earnings if the other person did not reciprocate. Results showed that scores were usually equal at the end of each session, and that subjects maintained close equality of scores throughout each session. When a response-cost contingency that punished the alternation of giving was introduced, however, large within-session score differences developed. These large differences continued to be produced after the response-cost contingency was removed. Finally, when subjects were told that the session could end at any moment, score differences were sharply reduced, indicating that production of score differences remained under the control of discriminative stimuli associated with the likelihood of reciprocation. The study suggests that with appropriate procedures, an experimental analysis of behavioral phenomena associated with the concept of “trust” may be possible.     

A nonrandomized minimax solution for passing scores in the binomial error model

A nonrandomized minimax solution is presented for passing scores in the binomial error model. The computation does not require prior knowledge regarding an individual examinee or group test data for a population of examinees. The optimum passing score minimizes the maximum risk which would be incurred by misclassifications. A closed-form solution is provided for the case of constant losses, and tables are presented for a variety of situations including linear and quadratic losses. A scheme which allows for correction for guessing is also described.This work was performed pursuant to Grant No. NIE-G-78-0087 with the National Institute of Education, Department of Health, Education, and Welfare, Huynh Huynh, Principal Investigator. Points of view or opinions stated do not necessarily reflect NIE position or policy and no official endorsement should be inferred. The editorial assistance and comments of Anthony J. Nitko and of Joseph C. Saunders are gratefully acknowledged.     

A modified beta binomial model with applications to multiple choice and taste tests

A modified beta binomial model is presented for use in analyzing ramdom guessing multiple choice tests and certain forms of taste tests. Detection probabilities for each item are distributed beta across the population subjects. Properties for the observable distribution of correct responses are derived. Two concepts of true score estimates are presented. One, analogous to Duncan's empirical Bayes posterior mean score, is appropriate for assessing the subject's performance on that particular test. The second is more suitable for predicting outcomes on similar tests.This research was made possible by a grant from the Center for Food Policy Research, Graduate School of Business, Columbia University.     

恒河猴对50以下数目的估计

本研究有６个从易到难的程序,每个程序有标准数目和比较数目,都是白卡片上的黑圆点。每次试验先呈现标准数目作为样本,强化后撤去,随后同时呈现标准数目和比较数目,令动物作二择一反应。实验结果表明,影响恒河猴数目估计的有两个主要因素,即标准数目和比较数目之间的数间距和这两个数目本身的大小。在数间距为４或大于４时,恒河猴能对５０以下的数作出估计;在数间距为２时,恒河猴能对９－２５的数作出估计,但不能对２７－４９的数作估计。作者以为,这里所进行的是一种相对的区域性的数目估计,但它仍然是一种数标签的过程。     

Family‐based Intervention for Legal System‐involved Girls: A Mixed Methods Evaluation

The increased proportion of juvenile court‐involved girls has spurred interest to implement and evaluate services to reduce girls’ system involvement. The purpose of this study was to examine the effectiveness of a family‐based intervention by using a dominant sequential mixed methods evaluation approach. First, we examined quantitative data using a quasi‐experimental design to determine whether the family‐based intervention reduced recidivism among court‐involved girls. Propensity score matching (PSM) was used to construct statistically equivalent groups to compare one‐year recidivism outcomes for girls who received the court‐run family‐based intervention (n = 181) to a group of girls on probation who did not receive the intervention (n = 803). Qualitative interviews (n = 39) were conducted to contextualize the quantitative findings and highlighted the circumstances that family‐focused interventions for court‐involved girls. Girls who received the program had slightly lower recidivism rates following the intervention. The qualitative findings contextualized the quasi‐experimental results by providing an explanation as to the girls’ family circumstances and insights into the mechanisms of the intervention. Results highlighted the importance of family‐focused interventions for juvenile justice‐involved girls. These findings have practical and policy implications for the use interventions—beyond the individual level—with adjudicated girls and offer suggestions for ways to improve their effectiveness using a community psychology lens. In addition, this paper includes a discussion of evaluating of juvenile court programming from a community psychology perspective including strengths, challenges, and considerations for future work in this area.     

Justification,excuse, and proof beyond reasonable doubt

The law requires criminal guilt to be proved beyond a reasonable doubt. There are two different approaches to construing this legal rule. On an epistemic approach, the rule is construed in terms of justified belief or knowledge; on a probabilistic approach, the rule is construed in terms of satisfying a probabilistic threshold. An epistemic construction of the rule has this advantage over a probabilistic construction: the former can while the latter cannot excuse the state from blame for a false conviction. This claim rests on an understanding of legal rules, legal justification for a finding of guilt and the central purpose of a criminal trial.     

Cosmology: What One Needs to Know

Cosmology, the study of the universe, has a past, which is reviewed here. The standard model—the Big Bang, or the hot, dense early universe that is still expanding—is based on observations that are basically consistent but which require additional input to improve the agreement. Out of the early universe came the galaxies and stars that shine today. The future of the universe depends on the density of matter: too much mass leads to the Big Crunch; too little leads to eternal expans ion and cooling. The dark-matter problem prevents us from knowing which will be the fate of the universe. Thelimits of what may be called "scientific" are addressed.