Experimental Design

Question 1

What are the 3 experimental designs?

Answer 1

• Independent design
• Repeated measures design
• Matched pairs design

Question 2

What is the independent measures experimental design?

Answer 2

One group does task, another group does another – each participant only takes part in one condition

Question 3

What are the benefits of using an independent groups design? (2)

Answer 3

• No order effects as participants only complete one condition
• Lower risk of demand characteristics as they are less likely to work out the intentions of the study

Question 4

What are the limitations of using an independent groups design?

Answer 4

• ## Can be affected by participant variables as there may be differences between the participants of each group that affect the validity of the results

Question 5

What is the repeated measures experimental design?

Answer 5

The whole group does one task and then the other – each participant takes part in all conditions

Question 6

What are the strengths of using a repeated measures experimental design?

Answer 6

• No participant variables as the same participants are used in both conditions
• Uses fewer participants so can be more cost-effective than independent or matched pairs design

Question 7

What are the limitations of using a repeated measures experimental design?

Answer 7

• Can be affected by order effects due to the participants being better or worse at the task the second time around
• Higher risk of demand characteristics as the participants do all the conditions

Question 8

What is the matched pairs experimental design?

Answer 8

It is independent measures however participants in each group are deliberately matched on attributes e.g. age, gender

Question 9

What are the strengths of using a matched pairs experimental design?

Answer 9

• Controls participant variables as the participants are matched, reducing the differences between them
• No order effects as a participant only does one condition
• Lower risk of demand characteristics as each participant only sees one condition

Question 10

What are the limitations of using a matched pairs experimental design?

Answer 10

• Time consuming to find good pairs
• Requires more participants than repeated measures
• If a participant drops out, the pair becomes unusable

Question 11

What is the technique called to overcome order effects?

Answer 11

Counterbalancing

Question 12

What is counterbalancing and how does it overcome the problem of order effects in repeated measures experimental design?

Answer 12

• Half of the participants do condition 1 then condition 2. The other half do condition 2 then condition 1
• This overcomes the order effects because it means there is order effects both ways, so they affect each condition equally

Question 13

What is the name of the technique used to overcome the issue of participant variables in independent groups design?

Answer 13

Random allocation

Question 14

What is random allocation and how does it overcome the problem of participant variables in independent groups design?

Answer 14

• Randomly allocate the participants of the study to each condition of the experiment
• This overcomes the problem as it means that each condition has equal chances for individual differences to appear, so participant variables are spread evenly across groups