Three-Way ANOVA Analysis by SAS Interaction Plot by Excel

Three-Way ANOVA

Analysis by SASInteraction Plot by Excel

The Design

Type of Crime: Burglary or SwindleCulture of Defendant: American or

ChineseSex of Juror: Female or MaleDV: Recommended length of

sentence

Read in the Data

Data JurySimulation;Infile 'C:\Users\Vati\Documents\

SimData\ANOVA3B-13.dat';Input Culture $ Crime $ Sex $

Sentence;

Omnibus Analysis

Proc ANOVA;Class Sex Culture Crime;Model Sentence = Sex|Culture|

Crime; Means Sex|Culture|Crime; run;

Results & Follow-Up

The triple interaction is significantConduct simple interaction analysisTest Culture x Crime for each sexI asked you to do the simple

interaction analysis even if the triple interaction was not significant

Simple Interaction Effects

Proc Sort; By Sex;Proc ANOVA;Class Culture Crime;Model Sentence = Culture|Crime;By Sex; run;

Results & Follow-Up

• For each simple interaction that is significant, test the simple, simple main effects.

• Effect of type of crime at given levels of culture and sex.

• I asked you to do these tests regardless of whether or not the simple interaction was significant

Simple, Simple Main Effects

Proc Sort; By Sex Culture;Proc ANOVA; Class Crime;Model Sentence = Crime;By Sex Culture; run;

The Comparisons Made

Compare length of sentence for burglars versus swindlers whenJuror is female, defendant is AmericanJuror is female, defendant is ChineseJuror is male, defendant is AmericanJuror is male, defendant is Chinese

Prepare an Interaction Plot• Enter the appropriate means into

Excel (2010)• These are for the female jurors

Insert, Charts, Line

Select “Line With Markers”

Tweak the Vertical Axis

Gee Whiz

Add Axis Titles

Enter Text in Title Box

Then do the same for the Vertical Axis

Enter Chart Title

Other Tweaks

• Resize the chart• Change fonts• Remove or change grid lines• Et cetera• Then copy the chart to Word,

PowerPoint, or other application.

Prepare the Second Plot

• We need a plot for the male jurors too.• Enter the appropriate data into Excel.• Tweak the plot so it has the same dimensions

as the previous plot.• If you do not, Excel may scale it in a way that

distorts the differences between the two plots.