What does homogeneity of variance mean in experimental research?

Homogeneity of variance refers to the assumption that different groups being compared in an experiment have similar or equal variances. This concept is crucial in many statistical analyses, particularly in ANOVA, where it is important that the variability of scores within each group is comparable to ensure that any observed effects are due to the treatments or conditions being tested rather than differences in variability.

When homogeneity of variance holds true, it means that the spread or dispersion of scores in each group is consistent, allowing for valid statistical comparisons. If the variances are significantly different, it can affect the validity of the results and lead to inaccurate conclusions. This makes the understanding of homogeneity essential for properly interpreting the outcomes of experimental research.