Technical characteristics of the peabody individual achievement test as a function of item arrangement and basal and ceiling rules

The effects that item order and basal and ceiling rules have on test means, variances, and internal consistency estimates for the PIAT mathematics and reading recognition subtests were examined. Seven items on the math subtest and one item on the reading recognition subtest were significantly easier or harder than their test placement indicated. The use of basal and ceiling rules had a pronounced effect on the means, variances, and reliabilities on the multiple choice math subtest, while the rules' effects on the reading recognition subtests were minor. Item order also affected scores on the math subtest.     

Intrachild variabilities: Will curtailment of testing harm minority children?

Compared intrachild variability of five-year-old children (49 black, 34 white) on the Primary Mental Abilities Test when subjects reached their fifth birthday after completing at least two years of preschool enrichment. Conclusions, although qualified on the basis of limited sample size, revealed wider intrachild variability with minority children. This suggests that abandonment of testing may increase instructional problems and possibly lower the quality of instruction provided minority and poor children.     

Cognitive and perceptual measures as predictors of fourth-grade achievement

This study used a multivariate approach and longitudinal design to examine the relationship of early perceptual and cognitive development to later school achievement. The extent to which a set of 4th-grade achievement measures could be predicted from a set of variables collected when the students were in first grade was determined through a series of canonical and multiple correlation analyses. These results were compared to results of an earlier phase of the study. Similarities between the two phases indicated that: (a) A measure of visual perception added significantly to the prediction of achievement afforded by consideration of sex and academic aptitude. (b) The variables used to predict achievement may differ somewhat between boys and girls. (c) The usefulness of sex as a predictor of school achievement depends upon the specific achievement area under consideration. Differences in the two phases involved the extent to which sex was a predictor of a specific achievement area.     

Interjudge agreement in classifying students as learning disabled

Eighteen judges with backgrounds in assessment, decision making, and learning disabilities were asked to use an array of information to differentiate learning disabled and nonlearning disabled students. Each judge was provided with forms containing information on 42 test or subtest scores of 50 school-identified LD students and 49 non-LD students. Judges were extremely inaccurate in their classifications and in little agreement with each other. Also, it appeared that different judges emphasized different factors when making their decisions. The results suggest that, given current definitions of the condition called “learning disabilities,” there is considerable doubt that school personnel can accurately and reliably identify such students.     

网球运动中的科技产品

科技能帮助运动员迅速提升训练水平.在网球运动中.教练员和相关工作人员(医务、力量师、体能师和理疗师)将一些新技术运用于训练、测试和监测中,优化运动员技术,降低运动损伤的发生.心率表、3D加速计、水合测试设备和雷达枪是网球运动员训练和监控的主要设备.     

Understanding the role of shaft stiffness in the golf swing

Theoretically, shaft stiffness can alter shot distance by increasing clubhead speed or altering clubhead orientation at impact. A 3D forward dynamics model of a golfer and flexible club simulated the downswing. A genetic algorithm optimized the coordination of the model’s muscles (four torque generators) to maximize clubhead speed. The maximum torque output and maximum rate of torque development from the torque generators were varied to simulate the swing of golfers that generate different clubhead speeds. Four shafts of varying stiffness (flexible, regular, stiff, and completely rigid) were entered into these simulations to examine the role that shaft flexibility had on clubhead speed and orientation at impact. Shaft stiffness was found to have a meaningful effect only on clubhead orientation (dynamic loft and dynamic close) at impact. There was no evidence to support the premise that matching the stiffness properties of the shaft with the golfer would improve clubhead speed.