1. Chapter 5 Factorial Designs

2. Factorial Essentials Factorial design = more than one IV
IVs referred to as “factors”
Identifying factorial designs
Notation system
Digits represent IVs
Numerical values of digits represent the # of levels of each IV
2x3 factorial (say: “two by three”)
2 IVs, one with 2 levels, one with 3 = 6 total conditions
2x4x4 factorial
3 IVs, with 2, 4, and 4 levels = 32 total conditions

3. Factorial Essentials Identifying factorial designs Factorial matrix
2x2 (two levels each of type of exam and presence of timer)
Timer No Timer
Math
Verbal
Presence of Timer
Exam Type

4. Timer No Timer ½ Timer Math This is a 2x3 design. Verbal
Presence of Timer
Exam Type
This is a 2x3 design.
Timer No Timer
Math
Verbal
Music
Presence of Timer
Exam Type
This is a 3x2 design.

5. I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test.
Timer
No Timer 5
Overall, is there an effect of presence of timer?

6. I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test.
Timer
No Timer 5 10
Overall, is there an effect of presence of timer?

7. Timer No Timer Math 8 5 Verbal 2
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 8 5
Verbal 2
6.5
3.5 5 5
Overall, is there an effect of presence of timer?
Overall, is there an effect of content type?

8. Timer No Timer Math 6 4 Verbal 8 2
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 6 4
Verbal 8 2 5 5 7 3
Overall, is there an effect of presence of timer?
Overall, is there an effect of content type?

9. Timer No Timer Math 5 Verbal 10
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 5
Verbal 10 5
7.5
7.5 5
Overall, is there an effect of presence of timer?
Overall, is there an effect of content type?

10. Timer No Timer Math 8 2 Verbal
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 8 2
Verbal 5 5 5 5
Overall, is there an effect of presence of timer?
Overall, is there an effect of content type?

11. Timer No Timer Math 2 8 Verbal
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 2 8
Verbal
Main effect of presence of timer.

12. Timer No Timer Math 2 4 Verbal 6
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 2 4
Verbal 6
Main effect of presence of timer.
Main effect of content type.

13. Timer No Timer Math 2 Verbal 4
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 2
Verbal 4
Main effect of content type.

14. Timer No Timer Math 8 2 Verbal 5
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 8 2
Verbal 5
Main effect of presence of timer.
Interaction effect.

15. Timer No Timer Math 8 2 Verbal
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 8 2
Verbal
Interaction effect.

16. Timer No Timer Math 2 5 Verbal 8
I am interested to see whether performance on an exam is affected by projecting a countdown timer on the board during the test. I also believe that the type of content on the exam affects exam score.
Timer
No Timer
Math 2 5
Verbal 8
Main effect of content type.
Interaction effect.

17. Definition—Main Effects and Interactions
Overall effect of individual factors (IVs)
Interactions
When the effect of one factor (IV) depends on the level of the other factor (IV)
For every 2-way ANOVA you conduct, you will always report TWO main effects and ONE interaction
A) Main effect of IV1
B) Main effect of IV2
C) Interaction Effect

18. Reporting Results—Main Effects and Interactions
You must indicate which effects were significant and which were not.
Must include statement of statistical test in proper reporting format:
Test Letter (df)=Value, p decision
Must include a statement (in words) explaining the effect.
There is a significant main effect of presence of timer: F(1, 24) = 8.2, p<.05. Students taking an exam with a timer scored higher (M=8, SD=2) than students taking the exam without a timer (M=2, SD=2).

19. Reporting Results—Main Effects and Interactions
You must indicate which effects were significant and which were not.
Must include statement of statistical test in proper reporting format:
Test Letter (df)=Value, p decision
Must include a statement (in words) explaining the effect.
There is no significant main effect of exam type: F(1, 24) = 1.2, p=NS. Students taking an exam with a timer scored similarly (M=5, SD=2) to students taking the exam without a timer (M=5, SD=2).

20. Reporting Results—Main Effects and Interactions
You must indicate which effects were significant and which were not.
Must include statement of statistical test in proper reporting format:
Test Letter (df)=Value, p decision
Must include a statement (in words) explaining the effect.
There is a significant interaction effect of between exam type and presence of timer: F(1, 24) = 6.2, p<.05. Presence of timer improved performance for students taking the Math test, but did not have any effect on students taking the Verbal test.