experimental design

Question 1

experimental design

Answer 1

the different ways in which the testing of participants can be organised in relation to the experimental conditions

Question 2

independent groups design

Answer 2

participants allocated to different control groups where each group represents one experimental condition

Question 3

repeated measures design

Answer 3

all participants take part in all conditions of experiment

Question 4

matched pairs design

Answer 4

pairs of participants matched on variable(s) that may affect the DV
one member of pair assigned to condition A, the other B

Question 5

independent groups- strengths

Answer 5

• order effects not an issue

- demand characteristics less of a problem, less likely to guess aims

Question 6

independent groups- weaknesses

Answer 6

• individual differences/participant variables may be to blame for changes of the DV rather than the effects of the IV, less internal validity
• use random allocation to deal with this
• less economical, twice as many participants needed to produce equivalent data to repeated measures

Question 7

repeated measures- strengths

Answer 7

• participant variables are controlled

- more economical than independent groups, fewer participants needed

Question 8

repeated measures- weaknesses

Answer 8

• order effects (confounding variable), could cause boredom/fatigue leading to deterioration in performance on second task, or performance improves through practice
• to deal with this researchers use counterbalancing
• more demand characteristics, more likely to work out aim

Question 9

matched pairs- strengths

Answer 9

• order effects and demand characteristics less of a problem

- some reduction of participant variables

Question 10

matched pairs- weaknesses

Answer 10

• some reduction of participant variables, but participants can never be matched exactly
• matching time-consuming and expensive (especially if pre-test involved) so less economical

Question 11

random allocation

Answer 11

an attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other

Question 12

counterbalancing

Answer 12

an attempt to control for order effects in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order