Thus, I commend to your attention the results of a number of meta-analyses
done in the area of gifted and talented education.
In defining the approach, Mike Allen and Raymond Preiss describe in general terms the steps taken in a meta-analysis: A brief summary of the process for most meta-analyses
is found in the following five steps: (a) defining the issue, (b) collecting the available literature, (c) converting and correcting statistical information, (d) averaging the available data, and (e) considering the variation in the observed effect.
Relationships and their relative strength, gauged through meta-analyses
, would be the building-blocks for the map of science.
While it should be expected that meta-analytic generalizations may change over time as the experimental literature grows, it is less appreciated that multiple meta-analyses
asking the same question and performed within a short span of time (so that the available literature has changed little) may produce conflicting conclusions.
The goal of this paper is to present the results of meta-analyses
of published correlation coefficients between MLH and two fitness surrogates, growth rate and fluctuating asymmetry (FA).
reviewed such topics as the use of intelligence quotients  and social welfare programs.
Among other problems, publication bias results in inflated omnibus effect sizes in meta-analyses
, giving the impression that interventions have stronger effects than they actually do.
This volume consists of seven articles that provide systematic reviews and meta-analyses
in research-active fields in psychology that have generated a large number of primary studies.
To avoid these issues in systematic review writing, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses
(PRISMA) group, which mainly consists of Cochrane authors, has developed the PRISMA guidelines in 2009 (6).
Left atrial appendage closure (LAAC) with the Watchman device is noninferior to vitamin K antagonists (VKAs) and non-VKA oral anticoagulants (NOACs) for adults with nonvalvular atrial fibrillation (NVAF) and 1 additional stroke risk factor (strength of recommendation [SOR]: A, multiple meta-analyses
support the link between obesity and cancer, but substantial heterogeneity exists between studies.
Of the 5,659 RCTs included in 698 meta-analyses
, 93.7 and 6.3 percent were published as journal articles and unpublished, respectively.