The effect of causal diagrams on text learning

We examined the effect of studying a causal diagram on comprehension of causal relationships from an expository science text. A causal diagram is a type of visual display that explicitly represents cause-effect relationships. In Experiment 1, readers between conditions did not differ with respect to memory for main ideas, but the readers who studied the causal diagram while reading the text understood better the five causal sequences in the text even when study time was controlled. Participants in Experiment 2 studied only the causal diagram or only the text. There were no differences in memory for main ideas or the causal sequences between these groups. Results indicate that causal diagrams are not merely redundant with text and that causal diagrams affect understanding of causal relationships in the absence of a text. These findings supported the causal explication hypothesis, which states that causal diagrams improve comprehension by explicitly representing the implicit causal structure of the text in a visual format.     

The load-velocity profile differs more between men and women than between individuals with different strength levels

This study aimed to determine the suitability of the load-velocity relationship to prescribe the relative load (%1RM) in women, as well as to compare the load-velocity profile between sexes and participants with different strength levels. The load-velocity relationship of 14 men (1RM: 1.17 ± 0.19) and 14 women (1RM: 0.66 ± 0.13) were evaluated in the bench press exercise. The main findings revealed that: (I) the load-velocity relationship was always strong and linear (R² range: 0.987–0.993), (II) a steeper load-velocity profile was observed in men compared to women (Effect size [ES]: 1.09), with men showing higher velocities for light loads (ES: ? 0.81 and ? 0.40 for the y-intercept and 30%1RM, respectively), but women reporting higher velocities for the heavy loads (ES: 1.14 and 1.50 at 90%1RM and 100%1RM, respectively); and (III) while the slope of the load-velocity profile was moderately steeper for weak men compared to their strong counterpart (ES: 1.02), small differences were observed between strong and weak women (ES: ? 0.39). While these results support the use of the individual load-velocity relationship to prescribe the %1RM in the bench press exercise for women, they also highlight the large disparities in their load-velocity profile compared to men.     

Reconsidering Standards and Criteria

An early debate about the nature of setting standards on educational achievement tests centered on the extent to which resulting standards were arbitrary. Subsequent research in the area has advanced solutions to many practical standard setting problems, but the more fundamental issue regarding the empirical grounding of judgmental standard setting procedures has remained unresolved and largely unaddressed. This article reviews some of the salient elements of the debate about the nature of standard setting on educational assessments and suggests that the dispute can never be satisfactorily resolved within the current paradigm. A reconcep-tualization of the nature of standard setting is proposed, and suggestions for future research are provided.     

Variance Estimation for Differential Test Functioning Based on Mantel-Haenszel Statistics

This article concerns the simultaneous assessment of DIF for a collection of test items. Rather than an average or sum in which positive and negative DIF may cancel, we propose an index that measures the variance of DIF on a test as an indicator of the degree to which different items show DIF in different directions. It is computed from standard Mantel-Haenszel statistics (the logodds ratio and its variance error) and may be conceptually classified as a variance component or variance effect size. Evaluated by simulation under three item response models (IPL, 2PL, and 3PL), the index is shown to be an accurate estimate of the DTF generating parameter in the case of the 1PL and 2PL models with groups of equal ability. For groups of unequal ability, the index is accurate under the I PL but not the 2PL condition; however, a weighted version of the index provides improved estimates. For the 3PL condition, the DTF generating parameter is underestimated. This latter result is due in part to a mismatch in the scales of the log-odds ratio and IRT difficulty.     

The effect of beetroot juice supplementation on repeat-sprint performance in hypoxia

This investigation assessed the effect of dietary nitrate (NO₃^?) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO_2peak 53.1 ± 8.7 mL.kg^?1.min^?1) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYP_BR; 13 mmol NO₃^?) or NO₃^–depleted BR placebo (HYP_PLA). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO₂) was measured during the warm-up. There were no significant differences observed between HYP_BR and HYP_PLA for PPO or MPO; however, work decrement was reduced in the first RSE set in HYP_BR compared with HYP_PLA. There was a moderate effect for VO₂ to be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NO₃^? may not improve repeat-sprint performance in hypoxia but may reduce VO₂ during submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise.     

An early review of stroboscopic visual training: insights,challenges and accomplishments to guide future studies

ABSTRACT

Stroboscopic visual training (SVT) is a form of training in which an individual practices a task under intermittent visual conditions with the intention of enhancing subsequent performance under normal visual conditions. Training with stroboscopic devices is theorized to improve important visual, perceptual, and cognitive skills, which in turn transfers to enhanced sporting performance. Indeed, while there is an abundance of anecdotal evidence suggesting benefits of strobe training, empirical evidence is rarer and less conclusive. This lack of clarity is due, in part, to the challenging methodological issues faced when conducting experimental vision training studies in applied contexts. The present paper is an early review of the research to date with a focus on the key methodological decisions, such as the training and testing protocols employed, participant samples and control groups used, and practical considerations that enable such training in applied settings. Whilst still at an early stage, the existing studies point to SVT enhancing some aspects of foveal visual sensitivity and visual motor control, with notable benefits for some athletic tasks. Such improvements could have implications not just in sport, but in domains such as rehabilitation, education, and motor vehicle safety.