If a Researcher Performs a Meta-Analysis and Finds That the Mean

Multiple Choice

If a researcher performs a meta-analysis and finds that the mean d = 0.45, and the 95 percent confidence interval around this mean is (0.34, 0.56) , what can the researcher conclude?

A) All future studies of this effect will find effect sizes somewhere between 0.34 and 0.56.
B) Averaging across all of the literature, there really is no effect.
C) There is a medium effect, but it is unclear what the direction of the effect is.
D) Averaging across all of the literature, there is a medium effect, and this effect is statistically significant.