Experimental Designs

Question 1

What are the 3 types of experimental design?

Answer 1

Independent groups
Repeated measures
Matched pairs

Question 2

What is an independent groups design?

Answer 2

Participants take part in one condition only. Each condition has different participants.

Question 3

How is independent groups conducted? (Three points)

Answer 3

One-group of participants recruited.
Two-split participants into equal size groups.
Three-A different group is allocated to each condition.

Question 4

What are the two strengths of an independent groups design?

Answer 4

No order effects
Can be used when repeated measures design is inappropriate

Question 5

Why is there no order effects in independent groups design? What is this unlike?

Answer 5

Participants only take part in one condition so they will not get bored/fatigued or better at the task/have lasting effects from one condition to the next (context) unlike repeated measures design where participants take part in all conditions and could have order effects.

Question 6

Why can an independent groups design be used when repeated measures design is inappropriate? Give an example

Answer 6

For example quasi experiments when looking at gender differences. (Context) as each condition needs different participants

Question 7

What are the two disadvantages of independent groups design?

Answer 7

Individual differences may affect the DV
More participants are needed

Question 8

Why may individual differences affect the DV more in an independent groups design? What does this lower? What is this unlike?

Answer 8

There are separate groups of participants in each condition E.G.some participants could have a better memory which wouldn’t be suitable in a memory study (context) lowering the internal validity unlike repeated measures that uses the same group of individuals in all conditions to reduce the effect of individual differences

Question 9

What is a repeated measures design?

Answer 9

All participants take part in all/both conditions of the experiment

Question 10

Why are more participants needed for an independent groups design what is this unlike?

Answer 10

Two different groups are required for the different conditions (context) unlike repeated measures we use less participants as every participant takes part in all conditions