ANOVA

Question 1

What is an interaction in ANOVA

Answer 1

Interaction effects represent the combined effects of factors on the dependent measure. When an interaction effect is present, the impact of one factor depends on the level of the other factor. When interaction effects are present, it means that interpretation of the main effects is incomplete or misleading.

Question 2

Ordinal interaction

Answer 2

Interaction whose lines do not cross when plotted on a graph. Main effects can still be interpreted if there is a big difference in levels between the two lines, for example. If significant must still be followed up with pair-wise comparisons.

Question 3

Disordinal interaction

Answer 3

When the lines completely cross over. Main effects cannot be sensibly interpreted. This is the essence of an interaction effect: results and interpretations of one variable’s effect or impact must be qualified in terms of the impact of the second variable. To determine exactly which parts of the interaction are significant, the omnibus F test must be followed by more focused tests or comparisons.

Question 4

What do you do to the alpha level when conducting post hoc tests

Answer 4

Divide the alpha level by the number of post hoc tests you are conducting