Statistical power in randomized intervention studies with noncompliance

This study examined various factors that affect statistical power in randomized intervention studies with noncompliance. On the basis of Monte Carlo simulations, this study demonstrates how statistical power changes depending on compliance rate, study design, outcome distributions, and covariate information. It also examines how these factors influence power in different methods of estimating intervention effects. Intent-to-treat analysis and complier average causal effect estimation are compared as 2 alternative ways of estimating intervention effects under noncompliance. The results of this investigation provide practical implications in designing and evaluating intervention studies taking into account noncompliance.     

Concordance of self- and informant ratings of adults' current and childhood attention-deficit/hyperactivity disorder symptoms

Self-informant rating concordance for attention-deficit/hyperactivity disorder (ADHD) symptoms was assessed in 281 adults at the subscale (Inattention, Hyperactivity-Impulsivity) and individual symptom levels. Potential demographic, diagnostic, and informant identity moderators were also investigated. Concordance levels were similar for current and childhood symptoms. Although moderate positive correlations were found between self- and informant ratings on both subscales, informants endorsed more significant inattentive symptom severity. Kappa coefficients were variable, suggesting low concordance for certain symptoms. Sex and ADHD diagnosis moderated concordance, although effect sizes were small. These results have implications for the use of behavior rating scales in diagnosing ADHD, raise questions about the validity of self- and informant ratings, and support the need to investigate individual-differences variables that may impact concordance.     

The role of collaborative planning in children's source-monitoring errors and learning.

The aim of this research was to provide empirical evidence for a cognitive process that may contribute to children's learning from another person. A cornerstone of Vygotsky's sociocultural theory is that knowledge is internalized from others; however, the cognitive processes that support this transformation are underspecified. In a series of three studies, kindergarten children (mean age 5 years 8 months) participated in a categorization task with an adult in several collaborative and noncollaborative conditions and then were tested on their memory of who had performed which actions in the task. After the memory task, children were asked to recategorize the items on their own. Source-monitoring patterns and children's learning varied across conditions according to predictions. A measure of recoding was related to children's planning language that, in turn, predicted learning among the children. The results suggest that one process that contributes to children's internalization of knowledge may involve recoding of agent information and that recoding can be indexed by source-monitoring performance.     

Screening ADHD problems in the sports behavior checklist: factor structure, convergent and divergent validity, and group differences

The Sports Behavior Checklist (SBC) is subjected to a principal components analysis, and subscales are correlated with subscales of the Conners' Revised Parent Form and the Social Skills Rating System. Both of these analyses are conducted to determine the construct validity of the instrument. A subsample of lower socioeconomic status individuals is used to compare ADHD and control group differences on the subscales of the SBC. The authors find that a six-factor solution, as proposed by the original authors, accounted for 71.5% of the variance. As hypothesized, subscales on the SBC are low to moderately related to subscales on the anchor measures. Significant group differences are found on the Aggression, Emotional Reactivity, and Injury subscales. Implications and limitations are discussed.     

Neuropsychological Aspects of Pediatric Sickle Cell Disease

Sickle cell disease (SCD), a class of genetic disorders characterized by abnormal, sickled red blood cells, is a chronic illness that results in progressive cerebrovascular disease. Neurocognitive sequelae of clinically apparent cerebrovascular accidents in children with SCD are characterized by pervasive impairments, including decrements in general intellectual functioning, language and verbal abilities, visual-motor and visual-spatial processing, memory, academic achievement, and processing of subtle prosodic information. In contrast, subtle neurocognitive deficits in the areas of attention and concentration, executive function, and visual-motor speed and coordination appear to be associated with silent infarcts that are not necessarily detected on physical examination. Investigation of the disease course and associated neurocognitive sequelae suggest a disease-specific model of neuropsychological impairment. Recommendations are made for clinical and research efforts in the field of pediatric neuropsychology.     

The impact of competition on intrinsic motivation and creativity: considering gender, gender segregation and gender role orientation

The present research investigated whether competition influences children's artistic creativity and intrinsic motivation toward an art activity. Study 1 tested the hypothesis that boys' creativity would be enhanced by competition, while girls' creativity would be undermined. Fifty children (aged 6–10) made paper collages in one of two conditions; half competed for prizes and half did not. Results supported our hypotheses, and further showed that when children self-segregated by gender, the impact of competition was much more pronounced. Study 2 was designed to clarify the unexpected gender-segregation finding from Study 1. The Children's Sex Role Inventory [Boldizar, J.P. (1991). Assessing sex typing and androgyny in children: the Children's Sex Role Inventory. Developmental Psychology, 27, 505–515] was administered to 143 children (aged 6–11). One week later, these children made paper collages in one of four conditions; in addition to manipulating competition, assigned seating ensured that half of children were segregated by gender and half were not. Following the collage activity, an intrinsic and extrinsic motivation questionnaire was administered. Masculine children reported higher levels of intrinsic motivation when competing and when segregated by gender; they also reported higher levels of extrinsic motivation, especially when segregated by gender. These findings demonstrate that gender role is an important factor in determining children's responses to competition.