research methods- experimental designs

Question 1

independant groups

Answer 1

-one group does condition A and a second group does condition B
-p’s should be randomly allocated to experimental groups

Question 2

evaluation of independent groups

Answer 2

+no order effects
+will not guess aim
-participant variables
-less economical

Question 3

ao3 of independent groups: no order effects

Answer 3

-p’s are only tested once so can’t practice or become bored/tired
-controls an important CV

Question 4

ao3 of independent groups: will not guess aim

Answer 4

-p’s only tested once so are unlikely to guess the research aims
-therefore behaviour may be more ‘natural’ (higher realism)

Question 5

ao3 of independent groups: participant variables

Answer 5

-p’s in the two groups are different, acting as EV/CV
-may reduce the validity of the study

Question 6

ao3 of independent groups: less economical

Answer 6

-need twice as many p’s as repeated measures for the same data
-more time spent recruiting which is expensive

Question 7

repeated measures

Answer 7

same participants take part in all conditions of experiment

Question 8

evaluation of repeated measures

Answer 8

+participant variables
+fewer participants
-order effects
-participants guess aims

Question 9

ao3 of repeated measures: participant variables

Answer 9

-person in both conditions has the same characteristics
-controls an important CV

Question 10

ao3 of repeated measures: fewer participants

Answer 10

-half no. of p’s is needed than in independent groups
-less time spent recruiting p’s

Question 11

ao3 of repeated measures: order effects are a problem

Answer 11

-p’s may do better or worse when doing a similar task twice. also practice/ fatigue effects
-reduces the validity of the results

Question 12

ao3 of repeated measures: participants guess aims

Answer 12

-p’s may change their behaviour
-may reduce the validity of the results

Question 13

matched pairs

Answer 13

-two groups of p’s used but they’re related to eachother based on being paired on participant variable(s) that matter for the experiment

Question 14

evaluation of matched pairs

Answer 14

+participant variables
+no order effects
-matching is not perfect
-more participants

Question 15

ao3 of matched pairs: participant variables

Answer 15

-p’s matched on a variable that is relevant to the experiment
-controls participant variables and enhances the validity of the results

Question 16

ao3 of matched pairs: no order effects

Answer 16

-p’s only tested once os no practice or fatigue effects
-enhances validity of results

Question 17

ao3 of matched pairs: matching is not perfect

Answer 17

-matching is time-consuming and can’t control all relevant variables
-cannot address all participant variables

Question 18

ao3 of matched pairs: more participants

Answer 18

-need twice as many p’s as repeated measures for the same data
-more time spent recruiting which is expensive