Confidence Intervals for Ratios of Means and Medians
In studies where the response variable is measured on a ratio scale, a ratio of means or medians provides a standardized measure of effect size that is an alternative to the popular standardized mean difference. Confidence intervals for ratios of population means and medians in independent-samples designs and paired-samples designs are proposed as supplements to the independent-samples t test and paired-samples t test. The performance of the proposed confidence intervals are evaluated in a simulation study. The proposed confidence interval methods are extended to the case of a 2 × m factorial design that includes propensity score stratification and meta-analysis as special cases. R functions that implement the recommended confidence intervals are provided in the Supplemental Material file, available in the online version of this article, and are illustrated with several examples.
Bonett, Douglas G.; and Price, Robert M.. 2020. Confidence Intervals for Ratios of Means and Medians. Journal of Educational and Behavioral Statistics. Vol.45(6). 750-770. https://doi.org/10.3102/1076998620934125 ISSN: 1076-9986