On test collections for adaptive information retrieval

Traditional Cranfield test collections represent an abstraction of a retrieval task that Sparck Jones calls the “core competency” of retrieval: a task that is necessary, but not sufficient, for user retrieval tasks. The abstraction facilitates research by controlling for (some) sources of variability, thus increasing the power of experiments that compare system effectiveness while reducing their cost. However, even within the highly-abstracted case of the Cranfield paradigm, meta-analysis demonstrates that the user/topic effect is greater than the system effect, so experiments must include a relatively large number of topics to distinguish systems’ effectiveness. The evidence further suggests that changing the abstraction slightly to include just a bit more characterization of the user will result in a dramatic loss of power or increase in cost of retrieval experiments. Defining a new, feasible abstraction for supporting adaptive IR research will require winnowing the list of all possible factors that can affect retrieval behavior to a minimum number of essential factors.     

Developing prospective elementary teachers’ abilities to identify evidence of student mathematical achievement

This study investigated the effects of a classroom intervention on prospective elementary teachers’ ability to evaluate evidence of student achievement of mathematical learning goals. The intervention was informed by a framework for teacher education which aims to provide prospective teachers (PTs) with the skills needed to systematically learn from their own teaching practice. Prospective teachers (N = 160) participated in an intervention aimed at addressing their misconceptions about evidence of student learning. Results revealed that after the intervention, PTs were less likely to consider teacher behaviors to be evidence of student learning and more likely to discount student responses that were irrelevant to a specified learning goal. However, PTs were still likely to take procedural fluency as evidence of conceptual understanding and may have become overly skeptical of student understanding. Implications of the study suggest new ways of developing prospective teachers’ ability to systematically study and improve their teaching.     

A systematic review of injuries in recreational field hockey: From injury problem to prevention

ABSTRACT

The purpose of this study was to gather information from scientific literature related to all steps of Van Mechelen’s “sequence of prevention” for injuries applied to youth and adult recreational field hockey players. A systematic review was conducted in Medline via Pubmed and in SPORTDiscus via EBSCOhost. Twenty-six original studies were included. Regarding injury incidence (step 1) results showed several overall injury incidence rates (youth: 1.47 per 1,000 Athlete Exposure (AE) time-loss (TL) injury up to 11.32 per 1,000 AE TL ánd non-time loss (NTL) injury, adults: 2.2 NTL injury per 1,000 AE, 15.2 injury per 1,000 hours of sports participation). Considering games and practices, most injuries were sustained in games (youth: 4.9, adults: 7.87 per 1,000 AE). Considering body parts, highest injury incidence rates were found in body parts in the lower extremities (youth: knee injuries in games (0.33 per 1,000 AE), adults: hamstring injuries in pre-season (0.75 per 1,000 AE)) and injuries in the head/face/eye (youth: 0.66 and adults: 0.94 head/face/eye, 0.71 head/face and 0.63 concussion per 1,000 AE). Regarding aetiology (step 2), no studies were found. Regarding the efficacy of available interventions (step 3 and 4), one study was found among youth players, describing a warm-up programme.