3. Experimental Designs

Question 1

What is an independent group design ?

Answer 1

Participants are allocated to different groups where each group represents one condition

Question 2

What is the repeated measures design ?

Answer 2

Whereby all participants take part in all conditions

Question 3

What is the matches pairs design ?

Answer 3

Where pairs of participants are first matched on some variables that may affect the DV. Then one member of the pair is assigned to one condition and the other to another condition

Question 4

What is random allocation ?

Answer 4

An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other

Question 5

What is counterbalancing ?

Answer 5

An attempt to control for the effects of order in a repeated measures design

Question 6

How does counterbalancing work ?

Answer 6

Half the participants experience the conditions in one order and the other half isn’t the opposite order ?

Question 7

What is the method of the independent group design ?

Answer 7

If there are two levels of the IV, all participants experience one level of the IV. The performance would then be compared

Question 8

What is the method of the repeated measures design ?

Answer 8

All participants would participate in all levels of the IV, the two sets of data would then be compared to see if there was a difference

Question 9

What is the method of the matches pairs design ?

Answer 9

Participants are paired together on variables relevant to the study, then compare the performance of the two grouped

Question 10

Why is a matched pairs design used ?

Answer 10

It combats the issues with the repeated measures design

Question 11

What are the weaknesses of the independent group design ?

Answer 11

• participants in the different groups aren’t the same so there are participant variables
• more time consuming and expensive as there are twice as many participants

Question 12

What are the strengths of an independent group design ? (2)

Answer 12

• order effects are not a problem e.g fatigue effect or boredom
• less likely to guess aims so it minimised demand characteristics

Question 13

What are the weaknesses of the repeated measures design ? (3)

Answer 13

• each participant has to do at least two tasks & the order may be significant
• order effects arise because it could create boredom or fatigue so it could cause deterioration in performance on the second task
• more likely to guess the aims, demand characteristics tend to be more of a feature

Question 14

What are the strengths of the repeated measures design ? (2)

Answer 14

• participant variables are controlled as you are only comparing their data from one condition to another
• fewer participants are needed so it’s less time consuming to find participants etc.

Question 15

What are the weaknesses of the repeated measures design ? (2)

Answer 15

• participants can never me matched exactly even when using twins as there will still be important differences which affect the DV
• marching may be time consuming and expensive

Question 16

What are the strengths of the matches pairs design ? (3)

Answer 16

• order effects are less of Problem
• demand characteristics are less of a problem
• attempt to reduce participant variables

Question 17

How do you address the problem of participant variables in an independent groups design ? explain why

Answer 17

Participants should be randomly allocated, this attempts to evenly distribute participant characteristics across the conditions

Question 18

What technique is involved in counterbalancing?

Answer 18

ABBA
participant 1 : A B
Participant 2: B A

Question 19

What method attempts to deal with participant variables in the independent groups design?

Answer 19

Random allocation

Question 20

What method attempts to balance out order effects in the repeated mess design ?

Answer 20

Counter balancing