experimental design

Question 1

what are independent groups?

Answer 1

each participant only takes part in one condition of experiment

Question 2

what are the strengths of independent groups? (2)

Answer 2

● no order effects - participants only tested once

● less likely to guess aim and show demand characteristics

Question 3

what are the limitations of independent groups?

Answer 3

participants variables - two groups are different

Question 4

what are repeated measures?

Answer 4

all participants take part in both conditions of experiment

Question 5

what are the strengths of repeated measures? (2)

Answer 5

● no participants variables as same people are used in both conditions

● fewer participants needed - saves time and money

Question 6

what are the limitations of repeated measures? (2)

Answer 6

● order effects

● more likely to guess aim and show demand characteristics

Question 7

what are matched pairs? (2)

Answer 7

● participant matched on key characteristics that are thought to influence experiment

● then one participant from each pair allocated to a different condition of experiment

Question 8

what are the strengths of matched pairs? (3)

Answer 8

● participant variables are controlled due to matching process

● no order effects

● less demand characteristics

Question 9

what are the limitations of matched pairs? (2)

Answer 9

● time consuming

● can’t control all participant variables

Question 10

what are order effects? (3)

Answer 10

● order of conditions affecting participants behaviour

● e.g. performance in second condition better due to participants knowing what to do

● e.g. performance might be worse in second condition as they are tired

Question 11

what are demand characteristics? (2)

Answer 11

● participants change behaviour as a result of being in experimental situation

● behaviour no longer natural and acts as an extraneous variable