Why is assessing effect size important in research?

Assessing effect size is crucial in research because it provides clarity on the magnitude of differences between groups or variables, beyond simply determining if a statistically significant result exists. While statistical significance indicates whether the observed effect might be due to chance, effect size quantifies the strength of that effect. This is particularly important for researchers and practitioners because a statistically significant finding could have a small effect size, suggesting that the actual difference or relationship may not be substantial or meaningful in practical terms. Therefore, effect size offers a more comprehensive understanding of the results, allowing researchers to gauge the real-world implications of their findings and assess how closely they align with theoretical expectations or practical applications.