Laboratory versus field testing in cricket bowling: A review of current and past practice in modelling techniques

In cricket bowling, the reconstruction of elbow angle data is of utmost importance to the bowling versus throwing argument. This paper reviews system and modelling errors inherent in three-dimensional reconstruction processes with respect to the elbow extension tolerance set by the International Cricket Council. An understanding of these factors will enable more informed decisions about the choice of in-field versus laboratory testing in the calculation of elbow extension during bowling in cricket. Although there is a paucity of objective data related to in-field and laboratory testing, biomechanists must be guided by the greater accuracy of opto-reflective than video-based systems and so testing, at least for the present, should be conducted in a laboratory setting.     

Tennis

The study investigated differences in the one‐ (SH) and two‐handed (DH) backhands when hit flat, across‐court (AC) and down‐the‐line (DL), and with heavy topspin DL (TDL). The ability to disguise each of these backhands when hitting the above strokes was also assessed. Eighteen college‐level male tennis players, identified as having a high performance topspin SH (n = 6) or DH (n = 12) backhand drive, participated in the study. Players were required to hit three AC, DL and TDL backhands from the baseline with their preferred technique, while being filmed with two high‐speed video cameras operating at 200 Hz. The highest horizontal velocity backhand for each stroke was analysed. Results indicated that the sequential coordination of five body segments (hips, shoulder, upper arm, forearm, and hand/racquet rotations) was required for the execution of the SH stroke. The same number of segments were generally coordinated in the DH stroke (hips, shoulders, and varying degrees of upper arm and forearm rotations followed by hand/racquet movement). Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique. The SH backhand was characterised by a more rotated shoulder alignment than the DH stroke (SH: 119.1°; DH: 83.4°) at the completion of the backswing. At impact the ball was impacted further in front (SH: 0.59 m; DH: 0.40 m) and a similar distance to the side of the body (SH: 0.75 m; DH: 0.70 m). Players using the DH backhand technique delayed the horizontal acceleration of the racquet towards the ball (SH: 0.13 s; DH: 0.08 s prior to impact) and thus were capable of displaying a similar hitting motion closer to impact than players with a SH technique.     

Equating Exams as a Prerequisite for Maintaining Standards: Experience with Dutch centralised secondary examinations

National examinations in The Netherlands play an important role both as school-leaving exams and in providing access to tertiary education. For most subjects the exams consist of two parts: a part internal to the school which is constructed, set and marked by the individual schoolteacher; and a central part which is constructed by Cito, the Dutch National Institute for Educational Measurement, but administered and marked by the schools. For many years, and until the 1990s, the procedures for the construction of the exams and for setting cut-off scores remained largely unchanged. In the 1990s, in response to concerns over standards, studies were conducted which demonstrated the necessity and feasibility of using equating procedures. Acting upon the outcomes, the State Secretary for Education and Science provided funds for introducing and maintaining equating as a standard procedure in central exams. From 1994 onwards, more and more exams have involved formal equating procedures.     

The development, validation, and applicability of The Personnel Evaluation Standards

Michigan State UniversityAir Force Human Resources Laboratory     

Oregon's contribution to career information delivery, 1972–1987

Summary What was only an idea 15 years ago is now accepted practice and an essential component of career guidance programs. Quality information, flexible delivery systems, and active user services are fundamental components of systematic career information development, delivery, and use. In Oregon, a consortium management structure has made it possible for the Career Information System to serve a varied user base.The future lies in the same general directions. There are still millions of people who need but do not have ready access to useful career information. On the other hand, coordinated data is increasingly available; lower cost and more user-oriented information media are making computerized career information systems feasible for more organizations; and there is increasing evidence that user-controlled organizations such as the career information consortium are effective in helping agencies and institutions provide the career information that people need.Bruce McKinlay is Executive Director, Career Information System, University of Oregon.     

Spelling errors and reading fluency in compensated adult dyslexics

Generally, a person who is diagnosed as dyslexic remains diagnosably dyslexic all his/her life. However, occasionally, an individual compensates for his/her difficulties in some way, and by adulthood is no longer diagnosably dyslexic. In what ways are these compensated dyslexics different from both dyslexics and nondyslexics? We compared IQ, achievement test, and spelling error scores in adult dyslexics, adult nondyslexics, and adult compensated dyslexics (N=25) in the two studies reported here. The second study differed from the first in that the subjects were matched for age, education, IQ, and SES. In both studies, compensateds were significantly different from nondyslexics on the WRAT Spelling subtest and Reading Quotient scores. In the second study the compensateds differed from the nondyslexics in total raw score and average reading speed on Gray Oral Reading Test. On the other hand, they were different from dyslexics on all reading and spelling variables in both studies, except for PIAT Reading Comprehension in Study 2. Finally, in Study 2, the compensateds were different from both dyslexics and nondyslexics in average reading speed. In conclusion, it appears that compensation does not result from differences in IQ, education, or SES, though it may be influenced to some extent by sex. Compensateds appear very similar to nondyslexics in their reading and spelling skills; however, there appears to be a difference in the automaticity with which they apply these skills.     

The counseling needs of foreign students

This paper reports the findings of three studies of the counseling needs of international students at a medium sized University in the Midwestern region of USA. The studies were conducted over a period of five years (1977–83), and provide an historical perspective on the changes in student needs as well as in the programs designed to respond to these needs.     

Neuropsychology of Early-treated Phenylketonuria: Specific Executive Function Deficits

This study explored the hypothesis that children with early-treated phenylketonuria (PKU) are selectively impaired on executive function measures, even when still on diet. The rationale for this hypothesis is that even mild elevations in phenylalanine (Phe) can lead to lower central levels of biogenic amines, including dopamine (DA). We hypothesize that this mild DA depletion causes subtle prefrontal dysfunction, which in turn affects executive functions such as set maintenance, planning, and organized search. 11 preschool early-treated PKU children (M age = 4.64) and a sample of age- and IQ-matched unaffected peers (n = 11) were evaluated on a battery of executive function (EF) measures. In addition, a "non-executive function" task, recognition memory, was administered to all subjects. Group comparisons demonstrated that PKU children were significantly impaired on an executive function composite score; there were no group differences, however, in recognition memory. These results supported the hypothesized specific deficit in executive function. Furthermore, within the PKU group the executive function composite score was significantly negatively correlated with concurrent phenylalanine levels, even after controlling for the correlation between IQ and executive function skills. This second finding provides support for the proposed biochemical mechanism underlying the specific cognitive deficits.     

Axioms, Essences, and Mostly Clean Hands: Preparing to Teach Chemistry with Libavius and Aristotle

Andreas Libavius’ (c. 1555–1616) three part collection of letters, the Rerum chymicarum epistolica forma ... liber (1595–1599) is a particularly important text in fashioning the subject of chemistry as a demonstrative science and as a didactic discipline. Where Libavius’ Alchemia, which some have claimed to be the first textbook of chemistry, had mostly a humanist agenda, the Rerum chymicarum ... liber more directly sought to wrest the subject of “chemistry” away from Paracelsian adepts, and established the methodological basis for a specific form of knowledge suitable to the university. Making use of Aristotle’s Posterior analytics Libavius created a “floor-plan” for chemistry that integrated practical experience with natural philosophy, and could thus, he claimed, penetrate more deeply into the structure of nature than other academic disciplines.