Why is it important to consider effect size in experimental research?

Considering effect size in experimental research is crucial for evaluating the practical significance of findings. Effect size provides a quantitative measure of the magnitude of an intervention's impact, beyond just determining if the results are statistically significant. While statistical significance tells us if the findings are likely due to chance, effect size answers whether those findings are meaningful in real-world terms. For example, in a clinical trial, a statistically significant result may not translate into a large enough effect that would be beneficial to patients. Therefore, understanding the effect size helps researchers, practitioners, and policymakers make informed decisions about the implications and applications of the research.

In experimental research, merely knowing that a result is statistically significant is not sufficient. Effect size conveys the strength of the relationship or the impact and therefore influences the interpretation of results and their application in practice. This makes it especially important for translating research findings into actionable insights or policy changes.