Citation

Levine T, Asada KJ, Carpenter C. Commun. Monogr. 2009; 76(3): 286-302.

Copyright

(Copyright © 2009, Informa - Taylor and Francis Group)

DOI

10.1080/03637750903074685

PMID

unavailable

Abstract

Meta-analysis involves cumulating effects across studies in order to qualitatively summarize existing literatures. A recent finding suggests that the effect sizes reported in meta-analyses may be negatively correlated with study sample sizes. This prediction was tested with a sample of 51 published meta-analyses summarizing the results of 3,602 individual studies. The correlation between effect size and sample size was negative in almost 80 percent of the meta-analyses examined, and the negative correlation was not limited to a particular type of research or substantive area. This result most likely stems from a bias against publishing findings that are not statistically significant. The primary implication is that meta-analyses may systematically overestimate population effect sizes. It is recommended that researchers routinely examine the n-r scatter plot and correlation, or some other indication of publication bias and report this information in meta-analyses. KW: Aggression; Media Violence; Violent Video Games

Language: en