Experimental Designs

Question 1

What are Experimental Designs?

Answer 1

This refers to *how we use our participants in our experiments *
1) Repeated measures
2) Independent groups
3) Matched Pairs

Question 2

Describe and Evaluate Repeated Measures

Answer 2

The same participants take part in every condition
+ Cheap and Quick
+ Less individual differences (limiting extraneous variables)
- Order effects (to reduce use counterbalancing)
- Risk of demand characteristics
Prevention: Counterbalancing

Question 3

Describe and Evaluate Independent Groups

Answer 3

Participants take part in only one condition ; different groups, different conditions
+ No order effects
+ Reduced risk of demand characteristics
- More expensive and time consuming
- More participant variables
Prevention: Random allocation

Question 4

Describe and Evaluate Matched Pairs

Answer 4

Two groups of participants are used with *members paired on key particpant variables *e.g. gender, age
+ No order effects
+ Tries to contol ppt variables
- Time Consuming
- Difficult to find perfect matches
Prevention: Use an alternative design

Question 5

What is Counter balancing?

Answer 5

Changing the order of the tasks that ppts complete

Question 6

What are Pilot Studies?

Answer 6

*Small scale study *carried out before the actual study to check procedures, techniques and make changes
Reasons:
* Check if experimental design is appropriate
* Check the internal validity
* Check for extraneous/cofounding variables
* Check timings and ppt understanding/feedback

Question 7

What is the Floor & Ceiling effect?

Answer 7

Floor effect - when the task is too hard
*Ceiling effect *- when the *task is too easy *