Experimental Design

Question 1

Define experimental design

Answer 1

How participants are used within a study

Question 2

What are the 3 experimental designs?

Answer 2

• Independent groups
• Matched pairs
• Repeated measures

Question 3

What is the name for groups who complete the study in a different way

Answer 3

Conditions

Question 4

How many conditions can there be in a psychological study?

Answer 4

As many as is necessary

Question 5

Explain “independent groups”

Answer 5

• The study uses completely separate, different groups of participants for each study
• Independent of eachother

Question 6

Explain “matched pairs”

Answer 6

• Each group is independent of eachother
• Researcher matches up participants in one group with someone from the other group based on similar characteristics (e.g age, gender, IQ etc)

Question 7

Explain “repeated measures”

Answer 7

• The study uses the same group of participants for each condition
• Used repeatedly in the study

Question 8

Define participant variables

Answer 8

• Differences between participants within a group (e.g.
  variation in age, sex or social background)
• A kind of extraneous variable

Question 9

Define extraneous variable

Answer 9

All variables, other than the independent variable, which
could affect the results

Question 10

Define order effect

Answer 10

Refers to how the order of conditions can influence the outcome

Question 11

What are the 3 order effects?

Answer 11

• Fatigue effect (are tired from the experiment the second time they do it)
• Boredom effect (are bored of the experiment the second time they do it)
• Practice effect (practice the experiment and do better a second time, or figure out the aim and change their behaviors)

Question 12

What are demand characteristics?

Answer 12

When a participant figures out the aim of an experiment and acts in the way that they think they should

Question 13

Define counterbalancing

Answer 13

• A method to reduce order effects
• Half of the participants do the conditions in a different order to the other half

Question 14

Evaluate “independent groups”

Answer 14

Pros
- No order effects – because participants only take part in one condition, the results aren’t affected by practice, fatigue or
boredom – so the results are more genuine

Cons:
- Participant variables may have an effect on results
- More people are needed, so it is more effort and time-consuming

Question 15

Evaluate “matched pairs”

Answer 15

Pros:
- Reduced participant variables, because the variation between
groups is lower
- Avoids order effects, so counterbalancing is not necessary

Cons:
- Can be very time consuming
- It is impossible to pair people up accurately enough!

Question 16

Evaluate “repeated measures”

Answer 16

Pros:
- Fewer people are needed to take part
- Saves time and money
- Avoids participant variables distorting results

Cons:
- There is a higher chance of order effects occurring
(this can be corrected using
counterbalancing)