Experimental design

Question 1

What is experimental design

Answer 1

• the way in which pps are allocated to conditions

- each design has different strengths and weaknesses

Question 2

What is independent groups design

Answer 2

• different pps in each groups

- pps randomly allocated to each group

Question 3

Advantages of independent groups design

Answer 3

• no order effects
• demand characteristics less likely
• pps not lost between trials
• can be used when repeted measures is innappropriate

Question 4

Disadvantages of independent groups design

Answer 4

• number of pps-twice as many pps are needed to get the same amount of data
• there may be important individual differences between pps

Question 5

What are order effects

Answer 5

pps performance in conditons may be affected by the order in which they are performed

Question 6

What is a matched paired design

Answer 6

• where each pp is only in one group
• there are different pps in each condition but they are matched on important variables, like age, sex
• pps in two groups are matched for some relevant factor that you want to measure

Question 7

Advantages of matched pairs design

Answer 7

• controls for some individual differences

- no order effects-there are different people in each condition

Question 8

Disadvantages for matched pairs design

Answer 8

• need a large group of pps
• time consuming
• difficult to find pps who match
• expensive

Question 9

What is a repeated measures design

Answer 9

• each pp appears in both groups

- e.g. all pps do the task both with an audience and then without

Question 10

Advantages of repeated measures design

Answer 10

• controls for all individual differences as pps are tested against themselves
• requires fewer pps to get the same amount of data

Question 11

Disadvantages of repeated measures design

Answer 11

• can’t be used in studies where pps in one condition has large effects on response in the other, or where pps are likely to guess the purpose of the study
• demand characteristics
• order effects-but these can be reduced by counterbalancing

Question 12

What is counterbalancing

Answer 12

involves ensuring that each condition is equally likely to be first or second

• one half on the group will be in the AB condition
• the other half will be in the BA condition

Question 13

What is a control group

Answer 13

• where one group is used to provide baseline information
• one groups recieves the experimental treatment (manipulation of the IV)
• the control group acts as a comparison to the experimental group to study the effects