Relative Performance Levels Research Articles

Peak oxygen uptake and maximal power output of Olympic wheelchair-dependent athletes

To extend the existing data base on the cardiovascular capacity of wheelchair-dependent athletes, a maximum wheelchair exercise test was conducted by 48 athletes (8 females and 40 males) on a motor driven treadmill. Athletes were selected on availability from the representatives of eight different disciplines. For 36 subjects maximal external power was calculated on the basis of a separate drag test. Maximal oxygen uptake (VO2max) for the male population was 2.23 l.min-1 (32.9 ml.kg-1.min-1). Subjects were divided into functional categories according to the International Stoke Mandeville Classification, with one nonambulatory, nonparaplegic group classified as "LA." The LA group displayed the highest values while the class IC tetraplegic showed the lowest performance level. Classified over sports disciplines, male track and field representatives showed the highest VO2max (2.86 l.min-1, 44.9 ml.kg-1.min-1) and target shooting athletes the lowest (1.32 l.min-1, 16.3 ml.kg-2.min-1). Maximal power output was on average 81.1 W for the male population and varied from 65.8 W for class II athletes to 92.2 W for class LA. Between sports values ranged from 96.8 W for basketball players to 48.2 W for the archery representative. These data are useful for setting standards for maximally attainable performance levels in relation to sport, functional classification, or sex and underline the capability of the wheelchair-dependent to improve cardiovascular fitness.

User Field Testing of Laser Protective Lenses

A methodology for user field testing of military, laser protective lenses is described. It addresses the difficulty of testing the effects of their reduced light transmittance and color distortion when there is little or no control over the independent variables of illumination and environmental colors and contrasts. The thrust was to collect field data on more than 70 variables from over 250 soldiers, the rationale being that this “shotgun” approach would surface any critical problems. Moreover, if these field data were somewhat consistent with laboratory data, confidence could be placed in relative levels of soldier performance while wearing the lenses. No established methodology for such field testing existed, and a number of performance tasks had to be modified or constructed which were typical of military operations. The Farnsworth-Munsell 100-Hue Test was also conducted to investigate color discrimination ability while wearing the lenses. This test was intended to supplement other laboratory data and to serve as a reference for the field color distortion data. Analyses of the field test data validated the approach. The data base and procedures created will facilitate future research; there are clear indications of how to refine the tests now that the nature of response data has been more defined.

Neonatal morphometrics after endurance exercise during pregnancy

This study was designed to test the hypothesis that continuation of a regular running and/or aerobics program during late pregnancy at or above 50% of preconceptional levels limits fetal growth. Accordingly, detailed neonatal morphometric data were gathered in the offspring of two groups: 77 well-conditioned recreational runners and aerobic dancers who were delivered at term after continuing their exercise regimen at or above 50% of the preconceptional level throughout pregnancy and 55 matched controls. Daily exercise performance was quantitated before conception and throughout pregnancy. Significant reductions in birth weight (-310 gm), birth weight percentile (-20), ponderal index (-0.24), its percentile (-30), and the fetoplacental weight ratio (-0.7) were seen in the offspring of the exercise group whereas crown-heel length (51.4 cm) and head circumference (35.0) were similar in the two groups. Reductions in two-site skin-fold thickness (-1.5 mm), skin-fold percentile (-30), calculated percent body fat (-5.0%), and fat mass (-220 gm) in the offspring of the exercise group confirmed the asymmetric pattern of growth restriction and indicated that approximately 70% of the difference in birth weight could be explained by the difference in neonatal fat mass. In runners, the relative level of exercise performance in the last 5 months of pregnancy explained 40% of the variability in birth weight over an 1100 gm birth weight range. We conclude that continuation of a regular aerobic or running program at or above a minimal training level during late pregnancy results in an asymmetric pattern of growth restriction that primarily impacts on neonatal fat mass.

The effects of performance sampling methods on frequency estimation, probability estimation, and evaluation of performance information

This paper presents the results of two experiments investigating the effects of raters' methods of performance sampling on their ability to make accurate estimates and evaluations concerning the observed performance of multiple ratees. In two experiments, 120 college undergraduates took part in a performance observation task where they sampled the sales performances of six ratees (three good and three poor performers). The number of performance instances sampled for each ratee and the level of performance exhibited by the ratee (good, poor) were experimentally manipulated, in order to investigate their impact on raters' ability to estimate (a) the frequency of poor performance instances; (b) the frequency of the total sample (good and poor) of performance instances; and (c) the probability of poor performance (poor/total). Results indicated that estimates which were based upon a greater amount of observed information were more accurate than those based upon less information, whether probability, frequency, or sample size information was being estimated. In addition, subjects who equally sampled all ratees made more accurate relative estimates of ratee performance than did those who unequally sampled good and poor performing ratees. Finally, subjects were found to use performance probability information to produce accurate evaluative ratings concerning the relative levels of ratee performance, although performance ratings were found to be less reliable measures of relative ratee performance than were probability, frequency, and sample size estimates. Implications regarding performance sampling and the use of performance appraisal formats that elicit estimates concerning the frequency and probability of ratee performance are discussed.

Rational selective exploitation and distress: Employee reactions to performance-based and mobility-based reward allocations.

Prior research has demonstrated that allocators frequently distribute greater rewards to persons with high professional and geographic mobility than to persons with constrained mobility, especially among the very competent. This phenomenon has been termed rational selective exploitation. Do the recipients of such allocations actually experience this distribution rule as unjust and distressing, or is it a misnomer to refer to this phenomenon as exploitation? Two studies were conducted to explore this question. Study 1 was a laboratory experiment in which we manipulated relative performance level, relative mobility level, and allocation standard: performance based versus mobility based. Study 2 was a cross-sectional survey of actual employees in which subjects reported the degree to which performance and mobility were the basis for pay decisions at their places of employment, as well as the degree to which they perceived each standard to be fair. Both studies demonstrated that people regard mobility-based allocations as less fair and more distressing than performance-based allocations. Furthermore, the degree of distress resulting from mobility-based allocations is greater among persons who are disadvantaged by that standard: among people with constrained mobility, especially those who perform at high levels. These findings provide good support for the assertion that so-called rational selective exploitation is indeed distressing to employees. Reactions to this form of distress are also explored, and the implications of these findings for the allocation process are discussed.

Machine characterization based on an abstract high-level language machine

Measurements are presented for a large number of machines ranging from small workstations to supercomputers. The authors combine these measurements into groups of parameters which relate to specific aspects of the machine implementation, and use these groups to provide overall machine characterizations. The authors also define the concept of pershapes, which represent the level of performance of a machine for different types of computation. A metric based on pershapes is introduced that provides a quantitative way of measuring how similar two machines are in terms of their performance distributions. The metric is related to the extent to which pairs of machines have varying relative performance levels depending on which benchmark is used. >

Cognitive measures in assessing learning

AbstractDocumentation of what students learn, instead of only their relative levels of performance, is at the heart of any effective assessment of educational quality.

Lower respiratory illness in early childhood and lung function and bronchial reactivity in adolescent males.

We examined the relationship between lower respiratory illness (LRI) experience in early childhood and lung function and bronchial reactivity in 57 boys, 11 to 22 yr of age, whose histories of outpatient physician visits for wheezing and nonwheezing LRI had been documented prospectively during their first 6 yr of life. These boys were a subpopulation of 159 children whose early childhood LRI experience and spirometric performance had been studied an average of 4 yr previously. The majority of boys had been free of chronic respiratory symptoms in the 2 yr before evaluation. Boys with histories of 2 or more preschool wheezing illnesses had lower mean levels of performance for FEV1, FEF25-75, FEF50, FEF75, and FEV1/FVC than did boys who had zero or 1 preschool wheezing illness, replicating observations that had been made when the boys had been studied 4 yr previously. Boys with lower spirometric performance relative to the study population on initial testing continued to have lower relative levels of spirometric performance 4 yr later. Neither preschool wheezing nor nonwheezing illness experience was associated with the degree of methacholine sensitivity measured in adolescence. Increasing degrees of methacholine sensitivity were associated with lower levels of spirometric performance; however, preschool wheezing illness experience remained a significant correlate of spirometric performance after adjustment for level of methacholine sensitivity. We conclude that recurrent preschool wheezing illness in these adolescent boys was associated with persistently lower lung function, but not enhanced methacholine sensitivity, during the middle to late school years.

Minimum Disturbance Fertilizer Knifing for No-Till

ABSTRACT SUBSURFACE application of fertilizer in no-till cropping systems to increase efficiency of use must be accomplished within constraints of minimum soil and crop residue disturbance. We evaluated a number of applicator knife and coulter combinations representative of those currently being used for this purpose. Applicator performance was measured as width of soil disturbed along the path of implement travel, as a function of soil penetration depth, travel speed, and soil water content. Width of soil disturbance increased on the average over all applicators, with an increase in each of these factors. Soil water content proved to be the more critical in light of its effect on adherence of the heavy clay soil to applicator surfaces. Applicators were ranked according to the amount of soil disturbance caused under each set of operating conditions. Rankings provided a means of relating the physical characteristics of applicators to relative level of performance, hence a guide in selecting adequate design criteria for their improvement.

Is temporal order encoded automatically?

The reported experiment tested the suggestion that encoding of temporal order is automatic. Specifically, two of Hasher and Zacks’s (1979) automaticity criteria were examined: (1) that the amount and appropriateness of practice received would not affect acquisition of temporal information, and (2) that reliable individual differences would not be found on a test of memory for temporal order. Contrary to expectations, neither of these criteria was confirmed: Retention of temporal order increased with practice at three (or four) successive lists. And, reliable individual differences were indicated by the findings that subjects’ relative performance levels remained stable across lists, and that groups with higher average academic ability outperformed those with lower ability. Similar results were obtained for a flee-recall task (in which case they were expected). Problems of assessing degrees of nonautomaticity are discussed. Our data are seen to be in general conformity with Tzeng’s (e.g., Tzeng & Cotton, 1980) “study-phase” retrieval theory of temporal coding.

A self‐evaluation maintenance approach to school behavior

According to a recent self‐evaluation maintenance model, three variables — one's relative level of performance in school, the relevance of school to one's self‐definition, and the psychological closeness of comparison to others in the classroom — act in concert to affect self‐evaluation. By assuming that individuals behave so as to maximize self‐evaluation, knowledge of any two variables can be used to make predictions regarding behavior on the third. These predictions are spelled out for relevance, performance, and closeness. Associated with each prediction is a selective review of the literature and some implications for educators.

Expectancy Mediation of Concurrent Conditional Discriminations

Pigeons learned a pair of two-choice conditional discriminations concurrently. One was red/green identity matching. The other also employed red and green sample stimuli, but the choice alternatives were vertical vs. horizontal lines, with vertical being correct following red samples and horizontal being correct following green. Correct choices produced either food reward or a brief feedback tone. For the "congruent" group, a given sample reliably predicted a particular outcome (e.g., red-food, green-tone), regardless of whether the animal chose between colors or lines. For the "incongruent" group, the outcome that followed a particular sample was one thing on color-choice trials and the other thing on line-choice trials. For example, if a subject in the incongruent group received food for red matches and tone for green matches, then it received tone for correct vertical choices and food for correct horizontal choices. The congruent group reached significantly higher levels of correct performance on both problems than did the incongruent group. Moreover, these relative levels of performance were reversed when birds trained on the congruent procedure were switched to the incongruent procedure and vice versa, even though the stimulus-response requirements of both problems remained unchanged. The experiment provides further evidence that the outcome expectancies acquired in learning situations can be significant sources of stimulus control of instrumental behavior.

Individual Differences and Consistency of Performance During the Acquisition of a Complex Skill

Acquisition of complex multidimensional skills as presented by the MTPB was examined in this investigation. Results indicate individual differences in the acquisition of tasks as measured within this multiple-task battery. In addition, subjects had different acquisition rates across tasks. An additional finding was that there was a fair degree of consistency with respect to the subjects’ relative level of performance on the different tasks at any given point in training.

Evaluation of Egg-Laying Strains of Chickens in Different Housing Environments: Role of Genotype by Environment Interactions ,

Relative performance levels were compared for White Leghorn pullets of a selected and an unselected control strain in different laying-house environments in each of two experiments. Experiment 1 involved single-bird cages, separated-strain flocks in floor pens, and intermingled-strain flocks in floor pens. In addition, Experiment 2 included a three-bird cage environment. Genotype by environment interactions were detected in Experiment 1 for egg and body weights and in Experiment 2 for rate of lay after sexual maturity, livability, egg weight, hen-housed rate of lay, egg mass, body weight, and body weight gain. Although fewer genotype by environment interactions were found in Experiment 1, there was a distinct tendency for the strains to differ (or fail to differ) in similar ways in each of the three environments compared in the two experiments.Pullets of the more aggressive and socially dominant selected strain were generally superior in performance to unselected strain pullets when they were intermingled in floor pens, but those differences tended to disappear when pullets of the two strains were kept in separated-strain flocks. These results are taken as indirect evidence supporting the conclusion that differences in stress associated with the social environment may contribute to genotype by housing environment interactions for performance traits.Selected strain pullets generally were superior to unselected strain pullets when kept in cages with unlimited feed available. Unselected strain pullets put on excessive weight in cages as indicated by both linear and curvilinear regression analyses; the lighter the pullets were in body weight the greater the number of eggs laid after 40 weeks old. However, under the same conditions, selected strain pullets were, on the average, near optimal body weight for maximum egg production during the latter part of the laying year.

Acquisition and extinction of runway performance under escape, avoidance, and partial-avoidance procedures

The acquisition and extinction of locomotor responses of rats in a straight alley were examined for groups trained under escape, partial-avoidance, and avoidance procedures. During acquisition, one group (escape) received a 0-sec delay between being dropped into the alley and the onset of shock; two groups (partial avoidance) had 0.5- and 1-sec delays; and two groups (avoidance) had delays of 2 and 4 sec. On the final day of acquisition, the partial-avoidance rats displayed higher running speeds than either the escape- or avoidance-trained animals. The 4-sec avoidance group was consistently slower than all other groups. Speeds for all groups decreased during extinction, with rate of decline showing some relation to terminal acquisition level. Relative group performance levels proved to be consistent with a simple arithmetic model based on the assumption that changes in running speeds affect the aversiveness of the situation by altering US duration, CS duration, and effective US length.

Experimental Studies of Shift-Work I: A Comparison of ‘ Rotating ’ and ‘ Stabilized ’ 4-hour Shift Systems

Abstract Efficiency at ‘ mental ’ tasks was observed when performed according to a time schedule imposed by following one of two different 4-hour shift systems for a period of 12 consecutive days. Twenty-eight subjects were assigned either to a ‘ rotating ’ system, in which each 4-hour period of the 24 hours was worked once every 72 hours in a repeating cycle, or to a ‘ stabilized ’ system, in which the work periods were from 1230 to 1630 and 2400-0400 each day. In the rotating system, alterations in the level of several aspects of performance at different times of day were found to be related quite closely to concurrent fluctuations in body temperature arising from its natural circadian rhythm. A shift in the phase of this rhythm in response to the now sleep/waking cycle imposed by the stabilized system was accompanied by a corresponding change in the relative levels of performance observed in the two work periods. Thus in both systems body temperature was, in effect, a predictor of performance efficienc...

Performance and Physiological Indicants of Activation in a Vigilance Situation

Changes in performance and in four physiological measures during the course of a 1-hr. vigil and as a function of signal presentation rate were studied. Based on data obtained from six Ss during a total of 24 vigils, performance (% correct detections) and skin conductance decreased during the course of a vigil, heart rate remained constant, and neck tension level increased. There was no consistent tendency for Ss to perform at a higher level when signals were presented at a relatively fast rate than when presented at a slower rate. However, their performance was differentially affected by presentation rate, some performing better during the fast rate, some during the slow rate, and others showing no change. A positive relationship was found between the relative performance level manifested during the two rates (fast rate expressed relative to slow) and the relative magnitudes of skin conductance, heart rate, and neck tension level. The results were interpreted as supporting the hypothesis that variations in vigilance performance are in part determined by changes in activation level. The feasibility of recording physiological information in order to ascertain more accurately which factors are contributing to variations in performance in a given vigilance situation seems to have been demonstrated.

A Feeding Trial Conducted at Six Different Locations

OVER the past two decades, the random sample test has become a widely used tool in assessing the relative merits of commercial breeds and strains of poultry. For a number of reasons, random sample tests of commercial poultry rations have not been organized on an extensive scale, but comparisons of commercial rations are nevertheless made locally by a variety of organizations and individuals. Poultry rations are continually being compared by numerous research institutions, and results of these feeding trials, frequently conducted with a single breed or strain in a single environment, are used to recommend one formula over another for general use under a wide variety of conditions.In accepting such recommendations, we must assume that the order in which the rations rank under the test conditions can be used to predict the relative levels of performance when they are fed to other strains of birds in other environments, i.e…

CONTROL-DISPLAY-SU13JECT INTERACTION AND PERFORMANCE ON A COMPLEX PERCEPTUAL-MOTOR TASK∗

Abstract Two experiments employing tho Toronto Complex Coordinator (TCC) are reported which demonstrate that a consideration of control-display (C-D) linkages from the point of view of the operator yields information which is useful in predicting relative performance levels for various combinations of C-D linkages, locations of 13, and positions of the subject (S) relative to C and D. A method of describing tasks in terms of o C-.D-S matrix is described and illustrated with 10 such combinations. Experimental tests confirm the accuracy of predictions of relative performance levels made from entries in these matrices. It is also shown that the use of this form of task analysis may be extended to oilier tracking systems, such as the Two-Hand Coordinator, to predict accurately the optimal C-D linkage and location of the controls relative to S and D.