Factorial Design

Question 1

What are factorial designs?

Answer 1

Factorial experiments are experiments where multiple independent variables are manipulated.

Question 2

What is a factor?

Answer 2

Independent variable.

Question 3

What indicates the levels for a specific independent variable?

Answer 3

The value of the numeral. Ex: 2 x 2 means 2 levels for each variable.

Question 4

How many conditions?

Answer 4

Multiply each numeral. Ex: 5 x 3 = 15 conditions.

Question 5

How do we find if there is a main effect?

Answer 5

Calculate the average of each row and column. If the rows or columns are different than there is a main effect.

Question 6

How do we find if there is an interaction?

Answer 6

From graph: If not parallel than no interaction.
From table: If the difference between each column/row is different then there is an interaction.

Question 7

What are the types of factorial design? (3)

Answer 7

-Between-subject
-Within-subject
-Mixed design

Question 8

Pros and Cons of between-group design?

Answer 8

• Cons – Individual differences can become confounding variables, increasing the variance of scores.
• Pros – Avoid order and sequence effects

Question 9

How do we know it’s between-group design?

Answer 9

All participants are randomly assigned to each group.

Question 10

How do we know its within-group design?

Answer 10

All participants participate in ALL conditions. (choose this if you know the individual differences will be very large)

Question 11

Pros and Cons of within- group design.

Answer 11

Cons:
* The number of different treatment conditions can be high and time consuming
* (participant attrition, fatigue/practice)
Pros:
* Fewer individuals needed
* Reduces problems related to individual differences

Question 12

How do we know its a mixed factorial design?

Answer 12

Effect of manipulations on two groups of individuals. Ex: G1 does A1A2 but only B1 and G2 does A1A2 but only B2.

Question 13

Pros and Cons of mixed factorial design.

Answer 13

Pros:
* Control for unwanted individual differences, while investigating
specific individual differences
Cons:
* Limits the ability to make causal statements about the relationship
between variables
* Limits internal validity

Question 14

What are the advantages of factorial design?

Answer 14

• Increases external validity (Generalizations)
• Theories with two or more independent variables can only be
  tested via complex factorial designs

Question 15

What are the disadvantages of factorial design?

Answer 15

• Too many variables can result in: Huge experiments and requirements for multiple conditions.
• Interactions that are not easily interpreted