aim and background: in recent years, experts in the field of obsessive-compulsive disorder have been trying to measure the validity and efficiency of pharmaceutical interventions. the meta-analysis evaluated the effectiveness of medication on symptoms of patients with obsessive-compulsive disorder. methods and materials: this meta-analysis was conducted on studies during the past decade in iran...

Meta-analytic methods have been widely applied to education, medicine, and the social sciences. Much of meta-analytic data are hierarchically structured because effect size estimates are nested within studies, and in turn, studies can be nested within level-3 units such as laboratories or investigators, and so forth. Thus, multilevel models are a natural framework for analyzing meta-analytic da...

This study examined the change in countermovement jump (CMJ) performance across a microcycle of training in professional soccer players during the in-season period. Nine elite youth soccer players performed a CMJ test before and after 4 consecutive soccer training sessions of an in-season weekly microcycle. Training load was quantified using global positioning systems, heart rate, and rating of...

Anderson, Lindsay, and Bushman (1999) compared effect sizes from laboratory and field studies of 38 research topics compiled in 21 meta-analyses and concluded that psychological laboratories produced externally valid results. A replication and extension of Anderson et al. (1999) using 217 lab-field comparisons from 82 meta-analyses found that the external validity of laboratory research differe...

A confidence interval for effect sizes provides a range of plausible population effect sizes (ES) that are consistent with data. This article defines an ES as a standardized linear contrast of means. The noncentral method, Bonett's method, and the bias-corrected and accelerated bootstrap method are illustrated for constructing the confidence interval for such an effect size. Results obtained fr...

PURPOSE To examine variations in neuromuscular and hormonal status and their relationship to performance throughout a season of elite Australian Rules Football (ARF). METHODS Fifteen elite ARF players performed a single jump (CMJ1) and 5 repeated countermovement jumps (CMJ5), and provided saliva samples for the analysis of cortisol (C) and testosterone (T) before the season commenced (Pre) an...

BACKGROUND Analyzing social differences in the health of adolescents is a challenge. The accuracy of adolescent's report on familial socio-economic position is unknown. The aims of the study were to examine the validity of measuring occupational social class and family level of education reported by adolescents aged 12 to 18, and the relationship between social position and self-reported health...

The purpose of this meta-analysis was to examine the evidence for the effectiveness of exercise interventions on the resting blood pressure (systolic and diastolic) of obese children. A computerized search was made of seven databases using keywords. Effect sizes (ES) and 95% confidence intervals were calculated, and the heterogeneity of the studies was estimated using Cochran's Q-statistic appl...

Researchers recommend reporting of bias-corrected variance-accounted-for effect size estimates such as omega squared instead of uncorrected estimates, because the latter are known for their tendency toward overestimation, whereas the former mostly correct this bias. However, this argument may miss an important fact: A bias-corrected estimate can take a negative value, and of course, a negative ...