Question

For the following factorial designs, indicate how many cells would be created, and then indicate

how many main effects and interactions you would look for.

a. 3 x 2 design

b. 3 x 4 x 2 design

c. 2 x 2 x 2 x 2 design

Dovidio & Gaertner (2000) told students to make hiring recommendations for potential job candidates. Students read one application for a job from a fake candidate, recommending the candidate for the job (or not). The candidate was either high quality, ambiguous quality, or low quality. The candidate was also either white or black. What are the IVs and DVs? What’s the design? Identify and describe the main effects and interactions.

Table shows the percentage who recommended hiring the candidate	Weak qualifications	Ambiguous qualifications	Strong qualifications
Black	13%	45%	91%
White	6%	76%	85%

Answer 1

This is a factorial design.

there are two main effect of variables quality of education and race of candidate on the dependent variable hiring recommendation and one interaction of these two independent variable on dependent variable.

The dependent variable is the recommendation of hiring a student for job based on two independent variable quality of education such that Weak, Ambiguous or Strong and the race of the candidates such that black or white.

Dependent Variable: Hiring recommendations percentage.

Independent Variables: Quality of education, Race of candidate

Main Effect

The main effect can be understand by differencing the groups as shown below,

Table shows the percentage who recommended hiring the candidate	Weak qualifications	Ambiguous qualifications	Strong qualifications	Avegare
Black	13%	45%	91%	50%	Difference = 6%
White	6%	76%	85%	56%
Average	10%	61%	88%
	Difference, D=78%

There is very small difference between the groups of variable race and there is large difference between the groups of variable quality of education. Hence we can say that there is a main effect of quality of education on the hiring recommendation while race has approximately no main effect on hiring recommendation.

Interaction Effect

The interaction effect can be better seen in the scatterplot. the scatterplot is obtained in excel by following these steps,

Step 1: Step 1: Open Excel sheet and write the data value. The screenshot is shown below:

Step 2: INSERT>Recommended Charts>Line. The screenshot is shown below:

The plot is obtained as follow;

Conclusion: The parallel plot shown no interaction while non parallel plot shows interaction between two groups. From the plot we can see that there is an interaction between two groups percentage between weak qualification and ambiguous qualification and between strong qualification and ambiguous qualification.