MANOVA Problem Set

1.

Is there a sufficient correlation between the dependent variables to justify the use of MANOVA? YES! THE DEPENDENT VARIABLES ARE BOTH CONCEPTUALLY AND STATISTICALLY (r = .513) RELATED.

2.

Was the assumption of Equality of Covariance Matrices violated? Explain. NO! RESULT OF THE BOX'S TEST OF EQUALITY OF COVARIANCE MATRICES INDICATED NO VIOLATION (p = .463).

3.

Is there a statistically significant multivariate interaction effect? YES!

Identify the dependent variable(s) of this interaction effect. EMOTION ONLY

4.

What would be the proper follow-up tests for a statistically significant interaction effect? CONDUCT TWO SEPARATE ONE-WAY ANOVAs WITH TREATMENT AS THE INDEPENDENT VARIABLE FOR MALES AND FEMALES. IF THE ONE-WAY ANOVAs REPORT A STATISTICALLY SIGNIFICANT OMNIBUS, THEN PERFORM THE APPROPRIATE POST-HOC.

5.

Identify the proper post hoc analyses for any statistically significant univariate effects. Explain your answer. THE LSD IS ONE OF THE PROPER POST-HOCS BECAUSE THE EQUAL VARIANCES ASSUMPTION IS NOT VIOLATED.

6.

Is there a statistically significant multivariate gender effect on the dependent variate? YES! BUT BECAUSE THERE IS AN INTERACTION EFFECT, THIS MAIN EFFECT IS OF LITTLE INTEREST.

7.

Why would a researcher conduct a MANOVA instead of several ANOVAs? THERE ARE AT LEAST TWO REASONS TO CONDUCT A MANOVA INSTEAD OF A SERIES OF ANOVAs. (1) MANOVA IS A MORE POWERFUL STATISTICAL TECHNIQUE (I.E., IT IS BETTER ABLE TO DETECT DIFFERENCES IF THEY REALLY EXIST), (2) MANOVA CONTROLS FOR AN INFLATED TYPE I ERROR.

8.

Write a Results section for this research.

Correlations

Box's Test of Equality of Covariance Matricesa

Multivariate Tests c

Levene's Test of Equality of Error Variances a

Tests of Between-Subjects Effects

1. Treatment

2. Gender

3. Treatment * Gender

Tests of Between-Subjects Effects

1. Treatment

2. Gender

3. Treatment * Gender

Tests of Between-Subjects Effects

Treatment

Multiple Comparisons

Tests of Between-Subjects Effects

Treatment

Multiple Comparisons

Tests of Between-Subjects Effects

Treatment

Treatment