Improving the Bandwidth Selection in Kernel Equating

We investigate the current bandwidth selection methods in kernel equating and propose a method based on Silverman's rule of thumb for selecting the bandwidth parameters. In kernel equating, the bandwidth parameters have previously been obtained by minimizing a penalty function. This minimization process has been criticized by practitioners for being too complex and that it does not offer sufficient smoothing in certain cases. In addition, the bandwidth parameters have been treated as constants in the derivation of the standard error of equating even when they were selected by considering the observed data. Here, the bandwidth selection is simplified, and modified standard errors of equating (SEEs) that reflect the bandwidth selection method are derived. The method is illustrated with real data examples and simulated data.     

The influence of test‐based accountability policies on early elementary teachers: School climate,environmental stress,and teacher stress

This study examined the potential influence of test‐based accountability policies on school environment and teacher stress among early elementary teachers. Structural equation modeling of data from 541 kindergarten through second grade teachers across three states found that use of student performance on high‐stakes tests to evaluate teachers indirectly was related to teachers’ professional investment via test stress in the environment. Although students in kindergarten through second grade do not take high‐stakes assessments, early elementary teachers reported high levels of stress associated with test‐based accountability policies. This study provides data across multiple states that test‐based accountability policies may have negative influences on school environment and teacher stress among early elementary teachers. Implications for practice and research are discussed.     

Different durations within the method of best practice affect the parameters of the speed–duration relationship

The aim of the study was to determine whether estimates of the speed–duration relationship are affected using different time-trial (TT) field-based testing protocols, where exhaustive times were located within the generally recommended durations of 2–15?min. Ten triathletes (mean?±?SD age: 31.0?±?5.7?years; height: 1.81?±?0.05?m; body mass: 76.5?±?6.8?kg) performed two randomly assigned field tests to determine critical speed (CS) and the total distance covered above CS (D?). CS and D? were obtained using two different protocols comprising three TT that were interspersed by 60?min passive rest. The TTs were 12, 7, and 3?min in Protocol I and 10, 5, and 2?min in Protocol II. A linear relationship of speed vs. the inverse of time (s?=?D??×?1/t?+?CS) was used to determine parameter estimates. Significant differences were found for CS (p?=?0.026), but not for D? (p?=?0.123). The effect size for CS (d?=?0.305) was considered small, while that for D? was considered moderate (d?=?0.742). CS was significantly correlated between protocols (r?=?0.934; p?D? (r?=?0.053; p?=?0.884). The 95% limits of agreement were ±0.28m?s^?1 and ±73.9?m for CS and D?, respectively. These findings demonstrate that the choice of exhaustive times within commonly accepted durations results in different estimates of CS and D?, and thus protocols cannot be used interchangeably. The use of a consistent protocol is therefore recommended, when investigating or monitoring the speed–duration relationship estimates in well-trained athletes.     

Systematic reduction of leg muscle activity throughout a standard assessment of running footwear

Purpose:This study aimed to investigate whether there is a systematic change of leg muscle activity,as quantified by surface electromyography(EMG),throughout a standard running footwear assessment protocol at a predetermined running speed.Methods:Thirty-one physically active adults(15 females and 16 males) completed 5 testing rounds consisting of overground running trials at a speed of 3.5 m/s.The level of muscle activity from 6 major leg muscles was recorded using surface EMG.The variables asse...     

Beliefs,Self-reported or Performance-Assessed TPACK: What Can Predict the Quality of Technology-Enhanced Biology Lesson Plans?

Journal of Science Education and Technology - Digital technologies have the potential to increase the quality of instruction; however, using digital technologies does not necessarily guarantee...