Chapter 6.3 - Experimental designs

Question 1

What is the experimental design?

Answer 1

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

Question 2

What is the independent groups design?

Answer 2

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

Question 3

What is the repeated measures design?

Answer 3

All participants take part in all conditions of the experiment

Question 4

What is the matched pairs design?

Answer 4

Pairs of participants are first matched on some variable(s) that may affect the DV. Then one member of the pair is assigned to condition A and the other to condition B

Question 5

What is random allocation?

Answer 5

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 6

What is 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

What is one strength of independent groups? (order effects)

Answer 7

Participants are less likely to guess the aims of the investigation and order effects are not a problem compared to repeated measures

Question 8

What is one limitation of independent groups? (participant variables)

Answer 8

The participants in the different groups are not the same in terms of participant variables and so any findings may be a result of participant variables. These differences may act as a confounding variable, reducing the validity of the findings
- random allocation is used to combat this issue

Question 9

What is one limitation of independent groups? (economical)

Answer 9

This design is less economical than repeated measures as each participant contributes to a single result and so twice as many participants would be needed - time and money on participants