Experimental Design

Question 1

What are the three main experimental designs

Answer 1

• repeated measures
• matched pair
• independent groups

Question 2

What happens in an independent group design

Answer 2

• this is where there are diff participants in each group / condition
  -> different set of participants per condition
  Usually used to compare gender, age etc differences

Question 3

What happens in a repeated measures design

Answer 3

• where the same participants are used in each condition to compare performances in each condition, knowing that the differences aren’t due to participant variables
• e.g. before and after eating chocolate

Question 4

What happens in a matched pair design

Answer 4

• where there are different participants in each condition but they’re matched on important variables e.g. age, sex & personality so comparisons can be made without one group being better than the other

Question 5

Pros and Cons of independent groups designs

Answer 5

Pros:
- no order effects
- less chance of demand characteristics

Cons:
- participant variables still can occur
- twice as many participants needed to obtain the same amount of data compared to having everyone do both conditions

Question 6

repeated measures pros and cons

Answer 6

Pros:
- less chance of participant variables as all do the test in all conditions
- fewer participants needed to get data
- necessary to avoid individual differences

Cons:
- order effects risk (improvements due to practice or fatigue effect)
- greater risk of demand characteristics as they participate in multiple conditions

Question 7

Pros and cons of matched pair design

Answer 7

Pros
- no order effects as condition happens once
- less chance of participant variables as differences minimised through matched

Cons
- twice as many participants required as repeated measures
- time consuming and hard to find matching participants

Question 8

What is random allocation in the experiment

Answer 8

Randomly assigning someone a condition to try control participant variables

Question 9

What is counterbalancing

Answer 9

• an attempt to control the effects of order in a repeated measures design: half the participants experience conditions in one order and the other half do so in the opposite order

Question 10

Why counterbalancing may be used

Answer 10

In case of order effects that could occur e.g. of u saw horror films one week u may still see them later (nightmares)