Experimental designs

Question 1

What are the three experimental designs?

Answer 1

• Independent groups
• Repeated measures
• Matched pairs

Question 2

What is an independent groups design?

Answer 2

• when two seperate groups of participants experience two different conditions of an experiment
• this means all participants only see one level of IV

Question 3

What are the strengths and weaknesses of independent group designs?

Answer 3

Strengths: No order effects and less demand characterisrics

Weakness:
- No control over participant variables, as the participants are different and may have different abilities that can change the DV. This increases the amount of confounding variables
- less economical

Question 4

What is repeated measures?

Answer 4

• All participants experience both conditions and all levels of the IV

Question 5

Evaluate repeated measures

Answer 5

Strengths = participant variables are very controlled and fewer participants are needed
Limitations = Order effetcs such as boredom and fatigue can act as confounding variables

Question 6

What is matched pairs design?

Answer 6

• Participants are paired together based on a variable that can affect DV
• each member expierences one level of the IV

Question 7

Evaluate matched pairs design

Answer 7

Strengths = No order effects and less demands characteristics

Weakness = Time consuming and expensive to match participants
- A large number participants are required
- there still may be important differences between participants

Question 8

What are the solutions to the weaknesses of independent groups design and repeated measures

Answer 8

• Independent group design = random allocation
• Repeated measures = counterbalancing

Question 9

what is counterbalancing?

Answer 9

• an attempt to solve the weaknesses of repeated mesures where one half of participants expierence the conditions in one order and the other half expierence it in another

Question 10

what is random allocation

Answer 10

• every participant has an equal chance of being in a condition