Experimental design (Indepdent/ repeated/ matched)

Question 1

Define independent measures design

Answer 1

• An expeirmental design in which
• Different groups of ppts are used for each level of the IV

Question 2

Strengths of independent measures design

Answer 2

As ppts are exposed to 1 level of the IV..
* Minimised order effect: (Practice/ fatigue effects) Wont get better or worse
* Minimised demand characteracteristics: Ppts are less likely to guess the aims of the study

Question 3

Weaknesses of Independent meaures design

Answer 3

• Risk of individual differences: If there are important individual differences between ppts in different conditions.
• Sampling: More ppts are needed/ samples may be smaller

Individual differences can be reduced by random allocation

Question 4

How can individual differences be reduced?

Answer 4

• Random allocation

ensures that participant variables are distributed equally across the different conditions

Question 5

Define repeated measures design

Answer 5

• An experimental design in which
• The same group of people perform every level of the IV

Question 6

Strengths of a repreated measures design

Answer 6

1. Lowered risk of ppt varibles: AS they are constant across the different conditions
2. Less ppts are needed: This is good when the ppts are hard to find or at risk.

Question 7

Weaknesses of repeated measures design

Answer 7

1. Risk of order effects: As ppts particpate in every level of the IV, they will perform the same task more than once, this could improve or worsen their performances.
2. Risk of demand characteristics: As ppts see the experimental tasks more than once.

Question 8

Define matched pairs design

Answer 8

• Ppts are arranged into pairs.
• These pairs are similar in ways that are important to the study.
• One member of each pair performs in a differnet condition.

Question 9

Strengths of matched pairs design

Answer 9

1. Reduced risk of demand characterisitics.
2. Reduced risk of ppts varibles ( Since participants are matched, any individual differences that could affect the results are balanced out between the groups)
3. Reduced risk of order effects

Question 10

Weaknesses of matched pairs design

Answer 10

1. Difficulty in Matching: It can be challenging to find participants who match closely on all relevant characteristics.
2. Samle size: Avaibility of matched pairs may be limited. Making the sample size small

Question 11

Why are twins the ideal matched pairs?

Answer 11

• Genetically the same
• Similar experiences