Selectivity bias and the determinants of SAT scores

The determinants of state-wide average SAT scores are estimated for 1982 in a regression analysis which corrects for the proportion of students taking the test. The selectivity correction has a large impact on the estimates of the effects of other variables. Little effect of schooling variables (teachers' salaries, teachers per pupil, other expenditures) is found in the selectivity-adjusted estimates, except that large schools seem to depress SAT scores and private schools enhance scores. State-wide high school graduation standards also do not explain SAT score variation. In contrast, several demographic variables are quite important, including family size, the college-educated fraction of the population, and female-headed households. We can explain some of the SAT score decline in the 1970s with these cross-section estimates, suggesting that the decline over time is not due to changing resources for schooling but, in part, to changing demographics. In particular, a large part of the recent SAT score decline was caused by the large families of the post-war baby boom.     

Relationship of performance on the sensory organization test to landing characteristics

Jump landing tasks have been used to assess landing characteristics and require significant sensorimotor feedback to maintain functional joint stability (FJS) throughout the task. Postural stability (PS) also requires significant sensorimotor feedback and control and would seemingly involve similar sensory feedback pathways. However, previous literature clarifying the relationship between these two processes, maintaining FJS and PS, is limited. 80 Special Tactics Operators. PS was assessed using the Sensory Organization Test (SOT). SOT variables included: Composite, Somatosensory, Visual, Vestibular, and Preference scores. Landing characteristics were assessed using motion analysis during a double-legged (DLSJ) and single-legged (SLSJ) stop jump task. Pearson’s correlation coefficients were calculated to assess the relationship between SOT scores and landing characteristics (α < .05). For the DLSJ, significant correlations were found between: Composite and peak posterior ground reaction forces (?.257), Vestibular and peak knee abduction moment (?.237), and Preference and initial contact hip flexion (?.297), peak hip flexion (?.249). For the SLSJ, significant correlations were found between: Somatosensory and peak vertical ground reaction forces (?.246); Preference and initial contact hip flexion (?.295), peak hip flexion (?.262). The results indicate that the SOT may not be a sensitive enough tool to assess sensorimotor control in a healthy, athletic population.     

Exploring trust in online health information: a study of user experiences of patients.co.uk

This feature has been co‐authored by Anna Cunningham and her supervisor Frances Johnson. It is based on the research Anna conducted for her dissertation, which she completed as part of her MA in Library and Information Management at Manchester Metropolitan University. The study explored how people assess the trustworthiness of online health information, and the participants were asked to talk aloud whilst viewing information on the consumer health information website patients.co.uk. The study confirmed that their assessment was based on the information usefulness and credibility as well as identifying the factors relating to information quality and website design that helped to form these judgements. A. M.     

Cognitive Analysis of Expert and Novice Troubleshooting Performance

The purpose of this study was to investigate the influence of mental models on the performance differences between expert and novice service technicians who troubleshoot faulty technical equipment. This study involved the use of behavioral and cognitive methods of analysis to identify and develop the ideal mental models that are used by expert technical troubleshooters. These two methods of analysis involved the identification of the specific tasks used during troubleshooting and the collection and analysis of the verbal protocols of expert and novice technicians as they attempted to identify faults in technical equipment. The results of the study showed definite differences between experts and novices. The experts were able to acquire and correctly interpret the initial symptoms of the problem, and from the interpretation of the initial symptoms the experts were able to represent the problem through the development of an accurate problem space. The sequences used by the experts to find faults in technical systems involved the generation of hypotheses that were used to reduce the size of the problem space and, therefore, to narrow the number of potential locations for the fault. In contrast, the novice subjects were unable to accurately interpret the initial symptoms of the problem. They were also unable to represent the problem through the development of an accurate problem space. The lack of an accurate problem representation resulted in the apparent random search for faults in the system.