How Can We Improve the Accuracy of Screening Instruments?

Screening for early reading problems is a critical step in early intervention and prevention of later reading difficulties. Evaluative frameworks for determining the utility of a screening process are presented in the literature but have not been applied to many screening measures currently in use in numerous schools across the nation. In this study, the accuracy of several Dynamic Indicators of Basic Early Literacy Skills (DIBELS) subtests in predicting which students were at risk for reading failure in first grade was examined in a sample of 12,055 students in Florida. Findings indicate that the DIBELS Nonsense Word Fluency, Initial Sound Fluency, and Phoneme Segmentation Fluency measures show poor diagnostic utility in predicting end of Grade 1 reading performance. DIBELS Oral Reading Fluency in fall of Grade 1 had higher classification accuracy than other DIBELS measures, but when compared to the classification accuracy obtained by assuming that no student had a disability, suggests the need to reevaluate the use of classification accuracy as a way to evaluate screening measures without discussion of base rates. Additionally, when cut scores on the screening tools were set to capture 90 percent of all students at risk for reading problems, a high number of false positives were identified. Finally, different cut scores were needed for different subgroups, such as English Language Learners. Implications for research and practice are discussed.     

A new approach to determining net impulse and identification of its characteristics in countermovement jumping: reliability and validity

Examining a countermovement jump (CMJ) force-time curve related to net impulse might be useful in monitoring athletes' performance. This study aimed to investigate the reliability of alternative net impulse calculation and net impulse characteristics (height, width, rate of force development, shape factor, and proportion) and validate against the traditional calculation in the CMJ. Twelve participants performed the CMJ in two sessions (48 hours apart) for test–retest reliability. Twenty participants were involved for the validity assessment. Results indicated intra-class correlation coefficient (ICC) of ≥ 0.89 and coefficient of variation (CV) of ≤ 5.1% for all of the variables except for rate of force development (ICC = 0.78 and CV = 22.3%). The relationship between the criterion and alternative calculations was r = 1.00. While the difference between them was statistically significant (245.96 ± 63.83 vs. 247.14 ± 64.08 N s, p < 0.0001), the effect size was trivial and deemed practically minimal (d = 0.02). In conclusion, variability of rate of force development will pose a greater challenge in detecting performance changes. Also, the alternative calculation can be used practically in place of the traditional calculation to identify net impulse characteristics and monitor and study athletes' performance in greater depth.     

Testing a communication network model of employee turnover based on centrality

This study tested Feeley and Barnett's (1997) Erosion Model (EM) of employee turnover which predicts that individuals who are more central in their communication network will be more likely to remain at their position (or less likely to turnover). Seventy employees from three different organizations were surveyed about their attitudes toward their jobs and were also asked to indicate (by checklist) which employees they spoke to regularly at work. Turnover data were obtained at 3 and 6 months time after the surveys were completed. Results generally supported the Erosion Model of employee turnover. Those employees with high Degree or number of links in the network were less likely to turnover. Employees who required fewer links to communicate to all others in the network (i.e., Closeness) were also less likely to turnover but this relationship only approached statistical significance (p = .06). Betweenness, defined as the frequency with which a person falls between pairs of other positions in a network, was also significantly related to employee turnover. It was also predicted, based on Feeley and Bamett's EM, that the relationship between network position and turnover would be mediated by an employee's level of commitment to the organization and his or her intentions to leave work. Closeness significantly predicted commitment while Betweenness and Degree were unrelated to commitment levels. Organizational commitment was negatively related to intentions to leave work and, unexpectedly, commitment levels were positively related to employee turnover. The results were discussed and the applications of this research for management practitioners were considered.