Between-subjects one-way ANOVA involves what assumption about the groups?

Between-subjects one-way ANOVA involves what assumption about the groups?

• A. Means are compared across independent groups
• B. The same participants are measured under all conditions
• C. It can only compare two groups
• D. It does not assume equal variances across groups

Answer: (A)

In a between-subjects one-way ANOVA, you’re looking at separate groups of participants, each group representing a different level of the factor, and you compare their means. The crucial point about the groups is independence: observations in one group come from different participants than those in other groups. This independence allows the analysis to test whether the group means differ beyond what would be expected by chance by partitioning variance into between-group and within-group components. That’s why the statement that means are compared across independent groups is the best fit. The other ideas don’t describe this design: measuring the same people under all conditions refers to a repeated-measures design, not between-subjects; ANOVA can compare more than two groups, not only two; and standard one-way ANOVA does assume equal variances across groups (homogeneity of variance), so saying it does not assume that would be incorrect.

In a between-subjects one-way ANOVA, you’re looking at separate groups of participants, each group representing a different level of the factor, and you compare their means. The crucial point about the groups is independence: observations in one group come from different participants than those in other groups. This independence allows the analysis to test whether the group means differ beyond what would be expected by chance by partitioning variance into between-group and within-group components.

That’s why the statement that means are compared across independent groups is the best fit. The other ideas don’t describe this design: measuring the same people under all conditions refers to a repeated-measures design, not between-subjects; ANOVA can compare more than two groups, not only two; and standard one-way ANOVA does assume equal variances across groups (homogeneity of variance), so saying it does not assume that would be incorrect.