Experimental Design

Question 1

Experimental design:

Answer 1

The different ways in which the testing of participants can be organised in relation to the experimental conditions.

Question 2

Independent groups design:

Answer 2

Participants are allocated to different groups where each group experiences one experimental condition.

Question 3

Repeated measures:

Answer 3

All participants take part in all conditions of the experiment.

Question 4

Matched pairs design:

Answer 4

Pairs of participants are first matched on some variables that may affect the DV. Then one member of the pair is assigned to Condition A and the other to Condition B.

Question 5

Random Allocation:

Answer 5

An attempt to control for participants variables in an independent groups design which ensures that each participant has the same choice of being in one condition as any other. By a random number generator.

Question 6

Counterbalancing:

Answer 6

An attempt to control for the effects of order in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order.

Question 7

Independent groups: Evaluation

Answer 7

1. The participants who occupy the different groups are not the same, differences could be due to participant variables.
2. Less economical, as you need twice the number of participants.
3. Order effects are not a problem, less likely to guess the aims.

Question 8

Repeated measures: Evaluation

Answer 8

1. Each participant has to do at least 2 tasks, the order of these tasks may be significant as there may have a continuing effect.
2. More likely participants will work out the aims.
3. Participant variables are controlled.
4. Fewer participants are needed.

Question 9

Matched pairs: Evaluation

Answer 9

1. Only take part in a single condition so order effects and demand characteristics are less of a problem.
2. Participants can never be matched exactly
3. May be time-consuming and expensive, particularly if a pre-test is required.