An alternative procedure for analyzing job analysis results for content-oriented test development

Content-oriented test development requires information derived from a comprehensive job analysis. The job data typically consist of task and skill statements identified by subject matter experts. These statements characterize a target job and are then used to develop the test plan and item budget. The predominant practice for combining data from the task and job skill domains to facilitate preparation of a test plan and item budget is an impressionistic approach. This study reports variations and extensions of an alternative quantitative procedure for linking task and job skill data (Hughes & Prien, 1989) using results obtained in field studies. The results indicate that the procedure reported by Hughes and Prien (1989) yields consistent results. Also, modifications to the procedure result in more detailed solutions.Dr. Charles Lawshe graciously contributed three sets of job analysis data to this research project. Dr. Lawshe also provided a very thoughtful and cogent critique of our attempts to express these thoughts to a user audience and for this we are grateful.     

The effects of violence on infants and young children: international perspectives on prevention

People become subject to political and social violence when governments fail to give priority to basic health care or education. Attempts to meet foreign obligations also produce severe economic recessions which further impede efforts to improve the general quality of life of disadvantaged populations. Since multiple factors contribute to violence, a multidisciplinary approach is best suited to address the problem. For example, poverty and its associated risks are linked to violence, but living in poverty does not necessarily engender violence. Living in poverty may, however, fuel high rates of child mortality, illiteracy, malnutrition, excessive population growth, street children, and familial disintegration. An integrated action program was developed in Brazil for at-risk individuals and their families based upon the idea of building and reinforcing family ties and intergenerational togetherness. Undernourished infants, street children, the handicapped, women subjected to violence, and neglected senior citizens received special interventions in the program described in the text.     

Self-Monitoring negative statements

We examined the effects of a self-monitoring program on reducing the frequency of negative statements of a student with mild mental retardation who was enrolled in a self-contained classroom at a middle school. A changing criterion design was used within a multiple baseline design across two classroom periods. Additionally, the frequency of positive statements was reported. The results showed a decrease in the number of negative statements, and an increase in the number of positive statements. Maintenance data collected up to 8 weeks after the program ended indicated that the student continued to emit positive rather than negative statements. The use of this procedure to decelerate undesirable behavior is discussed.     

Calibration of a color monitor for visual psychophysics

It has become common for stimuli used in visual psychophysical experiments to be presented on high-resolution color cathode-ray tubes (CRTs) such as the Barco CDCT 6551. These enable a flexibility of color, spatial-frequency content, temporal-frequency content, duration, size, and position that is not provided by most other media. CRTs are, however, not perfect; they suffer from the effects of temporal instability, spatial variability, lack of phosphor constancy, gun interdependence, and gun nonlinearity. This paper describes methods of assessing these aspects of monitor performance with respect to how significant each may be in psychometric terms. Although every application of CRT use in visual psychophysics is different, some general rules can be formulated to help ensure that unwanted effects are kept to a minimum. For the CRT used in this study (Barco CDCT 6551), a warm-up time of 30-45 min is necessary before chromatic and luminous stability ensues. Restriction of individual gun outputs to within 10%-90% of the possible range ensures that the effects of gun interdependence and lack of phosphor constancy are negligible. Calibration methods dealing with the linearization of gun output are also discussed.     

Potentiation of the pressor response to stress by tolbutamide in dogs

Tolbutamide has previously been shown to amplify the pressor effects of “exogenous” catecholamines in conscious dogs, possibly due to sensitization of the α₁-adrenoreceptor-mediated vasoconstriction. The objective of this study was to examine if tolbutamide also amplifies the pressor effects of “endogenous” catecholamines released during psychological stress (classical Pavlovian aversive conditioning). Experiments were conducted in β-adrenoreceptor-blocked (propranolol, 1 mg/kg, i.v.) conscious dogs (n=4) trained in classical aversive conditioning. Conditioning was accomplished by following a tone (CS+) with a 1/2 second shock; another tone (CS-) was not followed by any shock and served as control. With saline pretreatment, aversive conditioning (i.e., CS+) increased mean arterial pressure (MAP) only by approximately 4.7% when compared to CS-, whereas with tolbutamide (45 mg/kg, i.v.) pretreatment, the increase in MAP induced by CS+ beyond what was induced by the CS- (approximately 6.2%) was significantly (p<0.05) larger than that with saline pretreatment. In isolated canine femoral arterial segments (n=4), the vasoconstrictor effect of phenylephrine (an α₁-agonist) at 5×10^?6M (which was the EC₅₀ value) was amplified by 2×10^?2M of tolbutamide from 54.0±2.0% to 66.9±2.1%. In conclusion, tolbutamide amplifies the pressor effects of “endogenous” catecholamines in conscious dogs, possibly by sensitization of the α₁-adrenoreceptor-mediated vasoconstriction. This mechanism of action is novel and has not been reported with other agents.     

Shape from stereo: A systematic approach using quadratic surfaces

We used quadratic shapes in several psychophysical shape-from-stereo tasks. The shapes were elegantly represented in a 2-D parameter space by the scale-independentshape index and the scale-dependentcurvedness. Using random-dot stereograms to depict the surfaces, we found that the shape of hyperbolic surfaces is slightly more difficult to recognize than the shape of elliptic surfaces. We found that curvedness (and indirectly, scale) has little or no influence on shape recognition.     

Tensorial basis to the constancy of perceived object extent over variations of dynamic touch

Subjects wielded occluded rods, with or without attached masses, and reported the distances reachable with their distal tips. Experiments 1–3 compared wielding about the wrist, the elbow, and the shoulder. Experiments 4 and 5 compared free wielding, using the whole arm, with wielding only about the wrist. The two comparisons, respectively, were of spatial and temporal variations in the rod’s rotational inertia. Perceived extent was found to be constant in both comparisons. This constancy was tied to the inertia tensorI _ij defined about a point that remains a fixed distance from the object during wielding&#x2014;an invariant of the spatially and temporally dependent patterning of mechanical energy impressed upon the tissues of the body. Discussion focused on the reciprocal action and perception capabilities of multisegmented limbs, the tensorial relations in the neurobiology of dynamic touch, and the strategy of understanding perceptual constancy through invariants.