Optimal Sample Allocation in Group-Randomized Mediation Studies with a Group-Level Mediator

We derive sample-allocation formulas that maximize the power of several mediation tests in two-level–group-randomized studies under a linear cost structure and fixed budget. The results suggest that the optimal individual sample size is typically smaller than that associated with the detection of a main effect and is frequently less than 10 under parameter values commonly seen in the literature. However, the optimal sample allocation can be heavily influenced by the group-to-individual cost ratio, the ratio of the treatment-mediator to mediator-outcome path coefficients, and the outcome variance structure. We illustrate these findings with a hypothetical group-randomized trial examining a school-discipline reform policy. To encourage utilization of the sample allocation formulas we implement them in the R package PowerUpR and powerupr Shiny application.     

Taken out of context: differential processing in contextual and isolated word reading

Three experiments are reported that investigate the cognitive processes underlying contextual and isolated word reading. In Phase 1, undergraduate participants were exposed to 75 target words under three conditions. The participants generated 25 words from definitions, read 25 words in context and read 25 in isolation. In Phase 2, volunteers completed either an explicit recall task (Experiment 1), an implicit word stem completion task (Experiment 2) or both tasks (Experiment 3). Our findings provide converging evidence that contextual and isolated word reading elicit different patterns of cognitive processing. Specifically, Experiments 1–3 demonstrated that words read in context were remembered similarly to words generated from definitions: words from both conditions were recalled more frequently in the surprise memory task and selected less often to complete the word stems in the implicit memory task. The opposite pattern was noted for words read in isolation. Reading in context is discussed in terms of its greater reliance on semantic processing, whereas isolated word reading is discussed in relation to perceptually driven processes.     

COMPONENTS OF QUALITY COMMUNITY COLLEGE CHILD CARE PROGRAMS

A critical information literacy model centers libraries within the curriculum where students find, evaluate and use information in order to conduct successful research (Swanson, 2011). This report documents the process by which the El Centro College (Dallas County Community College District) librarians and the psychology faculty collaborated in bringing information and research skills into the psychology curriculum. The sessions included (a) the research process of finding articles in professional psychology journals, (b) instruction on creating references using NoodleTools ? (an integrated tool for note-taking, outlining, and building references), and (c) how to write in American Psychological Association (APA) style. The integration of the library sessions within the classroom setting of team teaching with the instructor suggests an ideal opportunity for educators to enhance the academic, research, and information literacy education for all students.     

Geo-Policy Barriers and Rural Internet Access: The Regulatory Role in Constructing the Digital Divide

A combination of geography, public policy, and commercial investment in information infrastructure combines to create geo-policy barriers that in turn structure the ability of rural citizens to access the Internet. A statistical study of 208 rural telephone exchanges in Texas combined with case studies from rural counties explores the impact of distance and policies aimed at enabling rural telephone connection on the presence of Internet service providers. Market territories, including exchange areas and LATAs, and the distance requirements of expanded local calling policy in Texas can both help and hinder Internet access in remote areas.     

Bunny Hill or Black Diamond: Differences in Advanced Course‐Taking in College as a Function of Cognitive Ability and High School GPA

College students commonly have considerable course choice, and they can differ substantially in the proportion of their coursework taken at an advanced level. While advanced coursework is generally viewed as a desirable component of a student's education, research has rarely explored differences in student course‐taking patterns as a measure of academic success in college. We examined the relationship between the SAT, high school grade point average (HSGPA), and the amount of advanced coursework taken in a sample of 62 colleges and 188,985 students. We found that both the SAT and HSGPA predict enrollment in advanced courses, even after controlling for advanced placement (AP) credits and demographic variables. The SAT subtests of Critical Reading, Writing, and Math displayed differential relationships with advanced course‐taking dependent on student major. Gender and race/ethnicity were also related to advanced course‐taking, with women taking more advanced courses in all major categories except for science, technology, engineering, and mathematics (STEM) where they took fewer, even after controlling for other variables. Socioeconomic status had a negligible relationship with advanced course‐taking. This research broadens our understanding of academic achievement in college and the goals of admissions in higher education.     

Predicting volleyball serve-reception at group level

In a group-serve-reception task, how does serve-reception become effective? We addressed “who” receives/passes the ball, what task-related variables predict action mode selection and whether the action mode selected was associated with reception efficacy. In 182 serve-receptions we tracked the ball and the receivers’ heads with two video-cameras to generate 3D world-coordinates reconstructions. We defined receivers’ reception-areas based on Voronoi diagrams (VD). Our analyses of the data showed that this approach was accurate in describing “who” receives the serve in 95.05% of the times. To predict action mode selection, we used variables related to: serve kinematics, receiver’s movement and on-court positioning, the relation between receiver and his closest partner, and interactions between receiver-ball and receiver-target. Serve’s higher initial velocities together with higher maximum height, as well as smaller longitudinal distances between receiver and target increased the chances for the use of the overhand pass. Conversely, decreasing alignment of the receiver with the ball and the target increased the chances of using the underhand-lateral pass. Finally, the use of the underhand-lateral pass was associated with lower quality receptions. Behavioural variability’s relevance for serve-reception training is discussed.     

A multidimensional approach to talent identification and selection in high-level youth Australian Football players

There is limited research in talent identification in youth Australian Football (AF), especially the factors that underpin selection into higher-level development programs. Therefore, this study explored age-related differences in high-level youth AF players and investigated characteristics influencing selection into a high-level development program. Anthropometry (stature, sitting height, body mass), maturity (estimated age at peak height velocity), motor competence (Körperkoordinationstest für Kinder), fitness (change of direction speed, lower body power and upper body muscular endurance) and coach skill ratings (kicking, marking and handballing) of 277 state academy players (U13-U15) were assessed. MANOVAs identified significant age-related differences for anthropometry, fitness, and coach skill ratings. Furthermore, 90.9 and 90.0% of U15 selected and deselected players were classified correctly. Selected players were more mature, taller, heavier, more explosive, faster at changing directions, and had superior kick technique and marking results. These results demonstrate considerable age-group performance outcome differences, highlighting that high-level academies should aim to select or deselect after 15 years of age. Additionally, it appears earlier maturing players are favoured for selection into a high-level academy. While practitioners must consider the confounding effect of maturation, early maturing players may be favoured for their ability to withstand increasing demands in higher-level youth AF.     

Research Supplement

When they were working in the Psychology Department of Meanwood Park Hospital the authors undertook a pilot study of attitudes towards mental retardation among secondary school pupils. The results indicate confusion about the nature and causes of mental retardation and highlight concerns about integration of children with special educational needs into mainstream education. As a result, a much larger investigation was conducted, which also attempted to promote positive attitudes. The results of the later study are being analysed. Catherine Kyle is now clinical psychologist at Ravenspark Hospital, Irvine, Ayrshire.