Experiment designs

Question 1

Repeated measures

Answer 1

Same participants used in each condition. Participants experience all conditions

Question 2

Repeated measures strength i

Answer 2

strength is that it removes individual differences

Which are differences in the ability of participants that may affect their performance in each condition

This is because the same participants are used in each condition, meaning that participants of exactly the same ability level are used

Therefore, any differences are likely to be due to the changes in conditions rather than changes in the participants

Question 3

Repeated measures strength V

Answer 3

a strength is that it clearly shows the effect of the IV on the DV

This is due to the fact that the same participants are used in each condition

Meaning its possible to be more certain that the only thing affecting the DV is the change in the IV and not differences in participants

Question 4

Repeated measures limitations d

Answer 4

a limitation is that demand characteristics are more likely

This is when participants perceive the demands of the experiment and act accordingly, lowering the internal validity of research because of the change in participants natural behaviour

This is because the same participants are used in each condition, making them more able to perceive the experiments demands

Question 5

Repeated measures limitation o

Answer 5

a limitation is that order effects become likely

Which are factors such as practice (learning effect) or tiredness (fatigue effect) that can affect the performance of participants in the second condition

This is because the same participants are used in each condition, making these factors more likely

Question 6

Independent groups

Answer 6

Different participant are used in each conditions

Participants only experience one condition

Question 7

Independent groups strength o

Answer 7

strength is that it removes the possibility of order effects

Which are factors such as practice (learning effect) or tiredness (fatigue effect) that can affect the performance of participants in the second condition

This is because the different participants are used in each condition, meaning no participant ever repeats a condition, making these factors impossible

Question 8

Independent groups strength d

Answer 8

strength is that demand characterises are less likely

These occur when participants perceive the demands of the experience that and act accordingly, lowering the internal validity of research because of the change in participants natural behaviour

This is because different participants are used in each condition, making them less able to perceive the experimenters demands

Question 9

Independent groups limitation i

Answer 9

a limitation is that it may suffer from the effect of individual differences

Which are differences in the ability of participants that may affect their performance in each condition

This is because the different participants used in each condition may have different abilities for the characteristic being tested, which is likely to affect the validity of research

Question 10

Matched pairs

Answer 10

Different, but similar participants are used in each condition

An effort is made to match the participants in each condition on factors such as age, sex, abilities which are relevant to the study

Question 11

Matched pairs strengths i

Answer 11

strength is that it limits the impact of individual differences

Which are differences in the ability of participants that may affect their performance in each condition

This is because participants were matched in each condition, meaning that participants of a very similar ability level are used in each condition

Question 12

Independent groups limitation p

Answer 12

a limitation is that it requires twice as many participants as a repeated measures design

Which may negatively affect the cost and practicality of research

This is because different participants are used in each condition, meaning twice as many participants need to be recruited to produce the same amount of data to that in a repeated measures design

Question 13

Matched pairs strengths o

Answer 13

it removes the possibility of order effects

Which are factors such as practice (learning effect) or tiredness (fatigue effect) that can affect the performance of participants in the second condition

this is because the different participants are used in each condition, meaning no participant ever repeats a condition, making these factors impossible

Question 14

matched pairs strength d

Answer 14

a strength of a matched pairs design is that demand characteristics are less likely

these occur when participants perceive the demands of the experiment and act accordingly, lowering the internal validity of research because of the change in participants natural behaviour

this is because similar but different participants are used in each condition, making them less able to perceive the experimenters demands

Question 15

matched pairs limitation i

Answer 15

may suffer from individual differences even though an effort has been made to match participants in each condition

these are differences in the ability of participants that may affect their performance in each condition

this is because matching is difficult that participants can never be truly matched

equally, participants may be matched for the wrong variable, meaning another (unmatched) variable may affect the validity of research

Question 16

matched pairs limitation t

Answer 16

limitation is that it requires twice as many participants as a repeated measures design

which may negatively affect the cost and practicality of research

this is because similar but different participants are used in each condition, meaning twice as many participants need to be recruited to produce the same amount of data to that in a repeated measures design

moreover, the cost of a matched pairs design is likely to increase further as the matching process can be difficult and expensive