Evaluating Growth for ELL Students: Implications for Accountability Policies

In recent years, many U.S. states have introduced growth models as part of their educational accountability systems. Although the validity of growth‐based accountability models has been evaluated for the general population, the impact of those models for English language learner (ELL) students, a growing segment of the student population, has not received sufficient attention. We evaluated three commonly used growth models: value tables or transition matrices, projection models, and student growth percentiles (SGP). The value table model identified more ELL students as on track to proficiency, but with lower accuracy for ELL students. The projection and SGP models were more accurate overall, but classified the fewest ELL students as on track and were less likely to identify ELL students who would later be proficient. We found that each model had significant trade‐offs in terms of the decisions made for ELL students. These findings should be replicated in additional state contexts and considered in the development of future growth‐based accountability policies.     

Peer choice – does reviewer self‐selection work?

The British Journal of Educational Technology (BJET) uses a novel system for obtaining referees by e‐mailing the abstracts of submissions to a panel of over 250 referees and allowing these individuals to choose which papers they would like to review. An analysis of 13 experienced referees showed that, of 473 reviews assessed, these referees were slightly more lenient than the editor and that electronic records provide useful data that can be mined in interesting ways.     

A descriptive study of step alignment and foot positioning relative to the tee by professional rugby union goal-kickers

This study describes foot positioning during the final two steps of the approach to the ball amongst professional rugby goal-kickers. A 3D optical motion capture system was used to test 15 goal-kickers performing 10 goal-kicks. The distance and direction of each step, as well as individual foot contact positions relative to the tee, were measured. The intra- and inter-subject variability was calculated as well as the correlation (Pearson) between the measurements and participant anthropometrics. Inter-subject variability for the final foot position was lowest (placed 0.03 ± 0.07 m behind and 0.33 ± 0.03 m lateral to the tee) and highest for the penultimate step distance (0.666 ± 0.149 m), performed at an angle of 36.1 ± 8.5° external to the final step. The final step length was 1.523 ± 0.124 m, executed at an external angle of 35.5 ± 7.4° to the target line. The intra-subject variability was very low; distances and angles for the 10 kicks varied per participant by 1.6–3.1 cm and 0.7–1.6°, respectively. The results show that even though the participants had variability in their run-up to the tee, final foot position next to the tee was very similar and consistent. Furthermore, the inter- and intra-subject variability could not be attributed to differences in anthropometry. These findings may be useful as normative reference data for coaching, although further work is required to understand the role of other factors such as approach speed and body alignment.     

High-intensity efforts in elite soccer matches and associated movement patterns,technical skills and tactical actions. Information for position-specific training drills

ABSTRACT

This study aimed to translate movement patterns, technical skills and tactical actions associated with high-intensity efforts into metrics that could potentially be used to construct position-specific conditioning drills. A total of 20 individual English Premier League players’ high-intensity running profiles were observed multiple times (n = 100) using a computerised tracking system. Data were analysed using a novel high-intensity movement programme across five positions (centre back [CB], full-back [FB], central midfielder [CM], wide midfielder [WM] and centre forward [CF]). High-intensity efforts in contact with the ball and the average speed of efforts were greater in WMs than CBs, CMs and CFs (effect sizes [ES]: 0.9–2.1, P < 0.05). WMs produced more repeated efforts than CBs and CMs (ES: 0.6–1.3, P < 0.05). In possession, WMs executed more tricks post effort than CBs and CMs (ES: 1.2–1.3, P < 0.01). FBs and WMs performed more crosses post effort than other positions (ES: 1.1–2.0, P < 0.01). Out of possession, CFs completed more efforts closing down the opposition (ES: 1.4–5.0, P < 0.01) but less tracking opposition runners than other positions (ES: 1.5–1.8, P < 0.01). CFs performed more arc runs before efforts compared to CBs, FBs and WMs (ES: 0.9–1.4, P < 0.05), however, CBs completed more 0–90° turns compared to FBs, CMs and WMs (ES: 0.9–1.1, P < 0.01). The data demonstrate unique high-intensity trends in and out of possession that could assist practitioners when devising position-specific drills.     

Multivariate analyses of individual variation in soccer skill as a tool for talent identification and development: utilising evolutionary theory in sports science

The development of a comprehensive protocol for quantifying soccer-specific skill could markedly improve both talent identification and development. Surprisingly, most protocols for talent identification in soccer still focus on the more generic athletic attributes of team sports, such as speed, strength, agility and endurance, rather than on a player’s technical skills. We used a multivariate methodology borrowed from evolutionary analyses of adaptation to develop our quantitative assessment of individual soccer-specific skill. We tested the performance of 40 individual academy-level players in eight different soccer-specific tasks across an age range of 13–18 years old. We first quantified the repeatability of each skill performance then explored the effects of age on soccer-specific skill, correlations between each of the pairs of skill tasks independent of age, and finally developed an individual metric of overall skill performance that could be easily used by coaches. All of our measured traits were highly repeatable when assessed over a short period and we found that an individual’s overall skill – as well as their performance in their best task – was strongly positively correlated with age. Most importantly, our study established a simple but comprehensive methodology for assessing skill performance in soccer players, thus allowing coaches to rapidly assess the relative abilities of their players, identify promising youths and work on eliminating skill deficits in players.     

Simulation of Fragment Impact on Multi-Layer Targets Using Contact Method

Cased explosives generate highly energetic fragments as their casing breaks up. Due to the complexity of casing fragment related behavior such as embedment, perforation and ricochet, it may be insufficient to use equivalent triangular pressure loading in fragment impact simulations. This simplified method may over- or under-predict the target response. Recently, a procedure using contact techniques has been proposed to overcome such difficulties. It has been shown that the new method has the inherent capability in modeling the multi-piece and multi-hit fragment impact problems in a more realistic way. To investigate the applicability of the proposed method to simulations involving multi-layer penetration, the selected problems of fragment impact on multi-layer targets are described in this paper. It is demonstrated that this method is capable of predicting the complicated multi-layer structural response caused by fragment impact and penetration. Modeling procedures and some technical issues are also discussed.