Experimental Design (+Pilot Studies)

Question 1

What are the 3 ways a participant can be allocated?

Answer 1

• Independent groups
• Repeated measures
• Matched pairs

Question 2

Independent groups

Answer 2

• Different participants are used in each of the conditions.

Question 3

2 advantages of Independent groups

Answer 3

• There are no order effects.
  > Participant does better/ worse on the second task
• Less chance of demand characteristics

Question 4

2 disadvantages of Independent groups

Answer 4

• Need more participants as each participant is only used once
• Individual differences
  > Unfair to compare the results of the two groups

Question 5

Repeated Measures

Answer 5

• Same participants used in all conditions.

Question 6

2 advantages of Repeated Measures

Answer 6

• No individual differences
  > Same person is measured in both conditions
• Fewer participants

Question 7

2 disadvantages of Repeated Measures

Answer 7

• Order Effects
• If there is a gap between the two testing conditions it is possible that some participants may not return for the second condition.

Question 8

Matched pairs

Answer 8

• Different, but similar participants are used in each of the conditions.
• Matched across the groups on any characteristics judged to be important for that particular study

Question 9

2 advantages of matched pairs

Answer 9

• No order effects

- Problems of individual differences are reduced

Question 10

2 disadvantages of matched pairs

Answer 10

• Matching is difficult

- Twice as many participants are needed - more costly

Question 11

What is a Pilot Study?

Answer 11

• Small scale trial run
  > Test procedure
  > Look for issues