In ANOVA, which term represents the variability due to differences between group means?

In ANOVA, which term represents the variability due to differences between group means?

• A. Between-group variation
• B. Within-group variation
• C. Total variation
• D. Residual variation

Answer: (A)

In ANOVA, total variability is split into two main sources: how much the group means differ from the overall grand mean, and how much individual observations vary within each group around their group mean. The part that comes from differences between the group means themselves is the between-group variation. It reflects how distinct the groups are from one another, and it’s the component that increases when group means are far apart. The within-group variation, by contrast, captures the spread of observations inside each group around its own mean. Total variation combines both sources. Residual variation is the unexplained portion, often tied to within-group noise in this framework. So the variability due to differences between group means is between-group variation.

In ANOVA, total variability is split into two main sources: how much the group means differ from the overall grand mean, and how much individual observations vary within each group around their group mean. The part that comes from differences between the group means themselves is the between-group variation. It reflects how distinct the groups are from one another, and it’s the component that increases when group means are far apart. The within-group variation, by contrast, captures the spread of observations inside each group around its own mean. Total variation combines both sources. Residual variation is the unexplained portion, often tied to within-group noise in this framework. So the variability due to differences between group means is between-group variation.