THE IMPACT OF ITEM DELETION ON EQUATING CONVERSIONS AND REPORTED SCORE DISTRIBUTIONS

A formal analysis of the effects of item deletion on equating/scaling functions and reported score distributions is presented. There are two components of the present analysis: analytical and empirical. The analytical decomposition demonstrates how the effects of item characteristics, test properties, individual examinee responses, and rounding rules combine to produce the item deletion effect on the equating/scaling function and candidate scores, In addition to demonstrating how the deleted item's psychometric characteristics can affect the equating function, the analytical component of the report examines the effects of not scoring versus scoring all options correct, the effects of re-equating versus not re-equating, and the interaction between the decision to re-equate or to not re-equate and the scoring option chosen for the flawed item. The empirical portion of the report uses data from the May 1982 administration of the SA T, which contained the circles item, to illustrate the effects of item deletion on reported score distributions and equating functions. The empirical data verify what the analytical decomposition predicts.     

THE NATURE OF OBJECTIVITY WITH THE RASCH MODEL

Although it has been claimed that the Rasch model leads to a higher degree of objectivity in measurement than has been previously possible, this model has had little impact on test development. Population-invariant item and ability calibrations, together with the statistical equivalency of any two item subsets, are supposedly possible if the item pool has been calibrated by the Rasch model. Initial research has been encouraging, but the implications of underlying assumptions and operational computations in the Rasch model for trait theory have not been clear from previous work. The current paper presents an analysis of the conditions under which the claims of objectivity will be substantiated, with special emphasis on the nature of equivalent forms. It is concluded that the real advantages of the Rasch model will not be apparent until the technology of trait measurement becomes more sophisticated.     

THE EFFECTS OF VIOLATIONS OF UNIDIMENSIONALITY ON THE ESTIMATION OF ITEM AND ABILITY PARAMETERS AND ON ITEM RESPONSE THEORY EQUATING OF THE GRE VERBAL SCALE

One of the major assumptions of item response theory (IRT)models is that performance on a set of items is unidimensional, that is, the probability of successful performance by examinees on a set of items can be modeled by a mathematical model that has only one ability parameter. In practice, this strong assumption is likely to be violated. An important pragmatic question to consider is: What are the consequences of these violations? In this research, evidence is provided of violations of unidimensionality on the verbal scale of the GRE Aptitude Test, and the impact of these violations on IRT equating is examined. Previous factor analytic research on the GRE Aptitude Test suggested that two verbal dimensions, discrete verbal (analogies, antonyms, and sentence completions)and reading comprehension, existed. Consequently, the present research involved two separate calibrations (homogeneous) of discrete verbal items and reading comprehension items as well as a single calibration (heterogeneous) of all verbal item types. Thus, each verbal item was calibrated twice and each examinee obtained three ability estimates: reading comprehension, discrete verbal, and all verbal. The comparability of ability estimates based on homogeneous calibrations (reading comprehension or discrete verbal) to each other and to the all-verbal ability estimates was examined. The effects of homogeneity of item calibration pool on estimates of item discrimination were also examined. Then the comparability of IRT equatings based on homogeneous and heterogeneous calibrations was assessed. The effects of calibration homogeneity on ability parameter estimates and discrimination parameter estimates are consistent with the existence of two highly correlated verbal dimensions. IRT equating results indicate that although violations of unidimensionality may have an impact on equating, the effect may not be substantial.     

EFFICIENCY OF LINEAR EQUATING AS A FUNCTION OF THE LENGTH OF THE ANCHOR TEST

One of the most widely used methods for equating multiple parallel forms of a test is to incorporate a common set of anchor items in all its operational forms. Under appropriate assumptions it is possible to derive a linear equation for converting raw scores from one operational form to the others. The present note points out that the single most important determinant of the efficiency of the equating process is the magnitude of the correlation between the anchor test and the unique components of each form. It is suggested to use some monotonic function of this correlation as a measure of the equating efficiency, and a simple model relating the relative length of the anchor test and the test reliability to this measure of efficiency is presented.     

论回溯推理的模态形式

回溯推理是一种使用非常广泛的逻辑方法，但是逻辑学界对回溯推理的认识并不一致，传统观点认为，回溯推理的逻辑形式是充分条件假言推理的肯定后件式，笔者认为，传统的认识有许多缺陷，应当对其进行改造，回溯推理是一种模态推理，并且给出了回溯推理的模态形式。该逻辑表达式有两个主要特征：一是推理前提在形式上保真；二是推理的结论具有或然性。     

运动对血液红细胞的影响

红细胞在运动中起着运输氧气、二氧化碳及营养物质等重要的作用,不同运动强度对红细胞的理化性质会产生不同的影响,运动同时对血液中红细胞免疫也产生了较大影响,这一点也是为大多数研究者所忽视的问题。通过全面了解运动对红细胞的影响,利用红细胞免疫指标监控运动训练,诊断过度疲劳,将会开拓人们的视野,对于全面了解运动对机体免疫力的影响将起到重要的促进作用。     

影响阴离子型增稠剂性能的因素

本文详细讨论了原料结构及配比、催化剂用量、反应温度等因素对阴离子型增稠剂增稠性能的影响。     

THE EFFECTS OF CURRICULUM ON PRESCHOOL CHILDREN'S PERCEPTIONS OF THE ELDERLY

Perceptions of the elderly were determined for 42 4‐ and 5‐year‐old children. The Social Attitude Scale of Ageist Prejudice (SASAP) was used to examine how these young children perceived elderly people after being exposed to a developmentally appropriate classroom curriculum that focused on the characteristics and positive aspects of the elderly. In a pretest‐posttest design, a decrease in prejudice score was found for children in the experimental group from pretest to posttest; an increase in prejudice score was determined for the control group. Results of this study also indicate that young children are more negative toward elderly persons’ abilities than toward their social characteristics and that level of grandparent visitation is unrelated to SASAP score.     

松寿丹对小鼠中枢神经系统的作用

本实验就松寿丹(SSHD)对小鼠中枢神经系统的作用进行了研究。实验结果表明:SSHD可增加小鼠的自发活动,并对电惊厥、回苏灵惊厥和氨基脲惊厥有明显对抗作用。实验结果提示:SSHD对小鼠的中枢神经系统具有兴奋和抑制的双向性作用,其作用可能与CABA能神经功能的改变有关。     

原子间偶极相互作用对系统动力学规律的影响

本文研究单模场中两个原子之间的偶极相互作用对系统本征能量的影响，并比较了计及原子间偶极作用与忽略原子间仍极作用时光子数的期望值．     

MEASURING SCIENCE INTEREST: RASCH VALIDATION OF THE SCIENCE INTEREST SURVEY

Students in the USA have fallen near the bottom in international competitions and tests in mathematics and science. It is thought that extrinsic factors such as family, community, and schools might be more influential than intrinsic attitudes toward science interest. However, there are relatively few valid and reliable measures of intrinsic factors such as interest relating to science. With the lack of intrinsic measures, it is difficult to determine the impact of extrinsic factors on the intrinsic construct. A fuller picture of the factors affecting intrinsic factors such as science interest will allow interventions to become more refined and targeted. Several studies suggest that student interest toward science affects the likelihood of the student pursuing advanced courses in science. The goal of this paper is to establish the validity and reliability of the Science Interest Survey and to determine if the survey meets the formal requirements of measurements as defined by the Rasch model. Results using both IRT and CRT analysis suggest that Science Interest Survey is an adequate measure of the unidimensional construct known as science interest. Results further suggest the Science Interest Survey is a valid and reliable measure for assessing science interest levels.