Effect Size in Standard Deviation Units in Educational Research
An effect size states how big a difference between two conditions is, in units of the spread of the scores, so that results from different studies and different tests can be compared on one scale. A learner afterwards can read a value such as d = 0.40 as "about four tenths of a standard deviation", tell it apart from a p-value or a claim of statistical significance, and say whether a reported effect is large enough to change what they do.
Questions this Concept answers
- Why does expressing a result in standard deviation units let two studies that used different tests be compared?
Effect size - Wikipedia
The page explains what an effect size is: a quantitative measure of how big a difference or relationship is, reported alongside — and distinct from — a significance test. It develops the standardized…