Explore simple Meta-analysis, based on graphical display of CIs, for effect sizes in original measurement units, and for standardised effect sizes (Cohen’s d).

The most basic meta-analysis consists of simple pooling over studies, weighted by sample size. This may be carried out in original units, or in standardised units. A simulation is provided for each of these, for the Case 1, Single Group design. For standardised units (pictured), enter the d and n values for up to 10 previous studies. Click the buttons to have Excel find and display the CI for d for each study, and for those studies combined. You can also enter d and n for an additional study (perhaps our current study) and click to show the CI for this study, and for all studies combined. Click to show the statistical significance test results: Exploration of examples will probably suggest that effect sizes (and sample sizes) are much more influential and informative than significance levels. For more, see our journal article.