达尔文医学的哲学启示

达尔文医学从本源上阐明队类疾病产生的偶然性与必然性的对立统一。其对进化论的重新反思和认识,具有重要的人文价值和现实意义。     

Principles for Designing Randomized Preventive Trials in Mental Health: An Emerging Developmental Epidemiology Paradigm

An emerging population-based paradigm is now being used to guide the design of preventive trials used to test developmental models. We discuss elements of the designs of several ongoing randomized preventive trials involving reduction of risk for children of divorce, for children who exhibit behavioral or learning problems, and for children whose parents are being treated for depression. To test developmental models using this paradigm, we introduce three classes of design issues: design for prerandomization, design for intervention, and design for postintervention. For each of these areas, we present quantitative results from power calculations. Both scientific and cost implications of these power calculations are discussed in terms of variation among subjects on preintervention measures, unit of intervention, assignment, balancing, number of pretest and posttest measures, and the examination of moderation effects.     

An Evaluation of the Validity and Fairness of the Graduate Management Admissions Test (GMAT) Used for MBA Selection in a UK Business School

The Graduate Management Admission Test (GMAT) has been shown to be a valid predictor of Masters of Business Administration (MBA) performance in the USA, but no UK validity studies have been published. This study uses a large sample of UK MBA students to examine the validity and fairness of GMAT. It is found that GMAT-Verbal is a good predictor of MBA examination performance but GMAT-Quantitative is not. It is also found that both components are unfair to native English speakers. The reasons for these findings are to be found in the nature of the criterion employed. Some observations are made regarding the consequences for best practice of the competitive and political context of MBA selection.     

任务难度对基于位置返回抑制时间进程的影响

在返回抑制的实验范式下,采用线索一靶子模式进行了视觉字母觉察实验、实验发现,返回抑制在线索与靶子之间的时间间隔（ＳＯＡ）为７００ｍｓ时出现,且在９００ｍｓ时消退。这与先前许多实验发现的返回抑制在ＳＯＡ为３００ｍｓ左右时出现的结果不一致。作者认为,实验任务的难度是影响返回抑制时间进程的一个重要因素。     

Tracking Substance Abusers in Longitudinal Research: Understanding Follow-Up Contact Difficulty

Studies examining follow-up contact difficulty provide useful information for planning longitudinal studies and for assessing the validity of follow-up data. Contact difficulty was examined among 96 substance abusers following substance abuse treatment. Interview completion rates at the 3-month and 6-month follow-ups were 93 and 97%, respectively. The extent of contact efforts required to complete follow-up interviews varied substantially but tended to be greater at the 3-month follow-up than at the 6-month follow-up. Contact difficulty was related to reuse of substances at the 3-month and at the 6-month follow-ups with reusers requiring greater contact efforts than abstainers. None of the baseline individual and contextual variables examined significantly predicted level of contact effort at follow-ups. Attrition-related validity implications are discussed along with practical suggestions for planning tracking efforts.     

SOCIAL VALIDATION: THE EVOLUTION OF STANDARDS OF COMPETENCY FOR TARGET BEHAVIORS

The use of social validation procedures has become widespread in recent years. Although most researchers have used social validation procedures to select target behaviors and to evaluate whether the changes produced by a treatment program should be considered socially useful, little attention has been focused upon using the social validation process to determine the optimal levels for target behaviors. This paper suggests several ways in which social validation procedures can be employed in order to select when and how much to change target behaviors.     

TEACHING RETARDED WOMEN A CLOTHING SELECTION SKILL USING COMMUNITY NORMS

Five institutionalized retarded women were taught a clothing selection skill to coincide with popular fashion. Normative data concerning popular styles of color-coordinated clothing were collected through observations of women's apparel in a local community. Using a puzzle simulation of a woman with alternative pieces of colored clothing, color coordination training was conducted using modelling, instructions, practice, praise, and feedback to teach popular selections of color combinations. A generalization training component with actual clothing was also included. Training was accompanied by large increases in percentage of popular color selections with the puzzle and actual clothing. The increases maintained over a seven- to 14-week followup period. Time efficiency measures supported the use of the simulation procedure as opposed to total reliance on actual clothing. The results underscore the utility of local norms in community preparation programs and the efficacy of instructional procedures for severely and profoundly retarded persons as part of their participation in the deinstitutionalization movement.     

A lower bound to the probability of choosing the optimal passing score for a mastery test when there is an external criterion

Recently there has been interest in the problem of determining an optimal passing score for a mastery test when the purpose of the test is to predict success or failure on an external criterion. For the case of constant losses for the two error types, a method of determining an optimal passing score is readily derived using standard techniques. The purpose of this note is to describe a lower bound to the probability of identifying an optimal passing score based on a random sample ofN examinees.The work upon which this publication is based was performed pursuant to a grant [contract] with the National Institute of Education, Department of Health, Education and Welfare. Points of view or opinions stated do not necessarily represent official NIE position or policy.     

Optimal item difficulty for the three-parameter normal ogive response model

In tailored testing, it is important to determine the optimal difficulty of the next item to present to the examinee. This paper shows that the difference that maximizes information for the three-parameter normal ogive response model is approximately 1.7 times the optimal difference –b for the three-parameter logistic model. Under the normal model, calculation of the optimal difficulty for minimizing the Bayes risk is equivalent to maximizing an associated information function.The views expressed herein, are those of the author and do not necessarily reflect those of the Department of the Navy.     

Fisher transformations for correlations corrected for selection and missing data

The validity of a test is often estimated in a nonrandom sample of selected individuals. To accurately estimate the relation between the predictor and the criterion we correct this correlation for range restriction. Unfortunately, this corrected correlation cannot be transformed using Fisher'sZ transformation, and asymptotic tests of hypotheses based on small or moderate samples are not accurate. We developed a Fisherr toZ transformation for the corrected correlation for each of two conditions: (a) the criterion data were missing due to selection on the predictor (the missing data were MAR); and (b) the criterion was missing at random, not due to selection (the missing data were MCAR). The twoZ transformations were evaluated in a computer simulation. The transformations were accurate, and tests of hypotheses and confidence intervals based on the transformations were superior to those that were not based on the transformations.