Experimental Design

Question 1

What are the 3 types of experimental designs?

Answer 1

Independent groups
Repeated measures
Matches pairs

Question 2

Define independent groups?

Answer 2

A type of experimental design where there are 2 separate groups doing 2 separate conditions

Question 3

What are the positives of using independent groups?

Answer 3

There are fewer demand characteristics - as participants only know about 1 condition
No order effect - you only take part in 1 condition, so that they don’t get bored or practised

Question 4

What are the disadvantages of using independent groups

Answer 4

More participants are needed

Individual differences as the people in each condition are different. (1 group may be better at the task)

Question 5

Define repeated measures?

Answer 5

A type of experimental design where there is only 1 group who’s participants do both conditions

Question 6

What are the advantages of repeated measures?

Answer 6

No individual differences are created as the participants doing each condition are the same

Less participants will be needed

Question 7

What are the disadvantages of repeated measures?

Answer 7

Demand characteristics - participants may realise what the experimenters are expecting and may perform to that expectation. Also the measure has to change (2 sets of words to be memorised
Order effect - either boredom or practise.

Question 8

How can we help get rid of the disadvantage of order effect?

Answer 8

Counterbalancing

Question 9

Define matched pairs?

Answer 9

A type of experimental design where there are 2 separate groups, but this time they are matches into pairs based on certain qualities, such as age or IQ. One of each pair participant in condition A and the other in condition B

Question 10

What are the advantages or matched pairs?

Answer 10

No order effect
Controls for individual differences. Can be more sure the IV is changing the DV rather than differences between the groups

Question 11

Explain a single blind trial?

Answer 11

Participants aren’t aware of the conditions they are in
This attempts to control for the confounding effects of demand characteristics

Question 12

Explain a double blind trial?

Answer 12

Neither the participant nor the researcher are aware of the aims of the investigations

Question 13

When are double blind trials commonly used?

Answer 13

Drug trials

Question 14

What are the disadvantages of matched pairs?

Answer 14

A large sample size is needed
It is time consuming to match the participants