Experimental Design

Question 1

What are experimental designs?

Answer 1

The way participants are allocated to experimental groups

Question 2

What are the three types of experimental design?

Answer 2

• Independent groups
• Repeated measures
• Matched pairs

Question 3

What is the independent groups design?

Answer 3

• Randomly dividing a group of participants into groups through a ballot system, random number generator etc
• Each group takes part in only one condition

Question 4

What are the strengths of the independent groups design?

Answer 4

• No order effects
• Can use same resources
• Participants unlikely to guess aim
• No need to wait between conditions

Question 5

What are the weaknesses of the independent groups design?

Answer 5

• Can’t control participant variables
• Needs lots of participants

Question 6

What is the repeated measures design?

Answer 6

• Recruit a group of participants and let them participate in all conditions
• All participants take part in all conditions then results are compared

Question 7

What are the strengths of the repeated measures design?

Answer 7

• Gets rid of participant values
• Don’t need as many participants

Question 8

What are the weaknesses of the repeated measures design?

Answer 8

• Order effects
• May not be able to perform in other condition immediately
• Needs different resources
• Participants can guess hypothesis

Question 9

What is the matched pairs design?

Answer 9

• A group of participants are recruited in pairs of similar values that are relevant to the experiment
• Participants are then randomly assigned to each condition, splitting the pairs
• Participants are assessed according to their partners

Question 10

What are the strengths of the matched pairs design?

Answer 10

• No order effects
• Can use same resources
• Participant variables are controlled to an extent
• Unlikely to guess aim
• No need to wait between conditions

Question 11

What are the weaknesses of the matched pairs design?

Answer 11

• If one pair drops out, the pair is lost
• Takes a long time to find a perfect pair
• Needs a lot of participants

Question 12

What are order effects?

Answer 12

How the order of the conditions affect the results of the experiment

Question 13

What is counterbalancing?

Answer 13

Having one half of the sample complete the conditions in one order, and having the other half complete it in reverse to REMOVE ORDER EFFECTS