research methods: experimental design

Question 1

what is experimental design

Answer 1

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

Question 2

what is an independent groups design

Answer 2

when 2 separate groups of participants experience 2 different conditions in the experiment.

Question 3

what is a repeated measures design

Answer 3

all participants take part in all conditions of the experiment

Question 4

what is a matched pairs design

Answer 4

pairs of participants are matched on a variable(s) that may affect the DV/ a relevant variable.
one member of each pair goes into each conditon

Question 5

what is counterbalancing

Answer 5

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

Question 6

what is random allocation

Answer 6

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

Question 7

evaluation: independent groups -weakness

Answer 7

the participants in each group are not the same so individual differences (participant variables) can impact the DV - so random allocation is used

Question 8

evaluation: independent groups - strengths

Answer 8

order effects are not an issue (where they would be in other repeated measures designs).
participants are less likely to guess the aim

Question 9

evaluation: repeated measures - weaknesses

Answer 9

order can act as a confounding variable
- participants could experience boredom/fatigue which can cause deterioration in performance.
participants may perform better through the effects of practice.
it is more likely participants will work out the when they experience all conditions, this means they are more likely to show demand characteristics than independent groups.

Question 10

evaluation: repeated measures - strengths

Answer 10

participant variables are controlled and fewer participants are needed.

Question 11

evaluation: matched pairs - strengths

Answer 11

participants only do one condition so order effects and demand characteristics are less of a problem than with repeated measures.

Question 12

evaluation: matched pairs - weaknesses

Answer 12

participants can never be matched exactly, so there will still be differences between them that will effect the DV.
matching can be time-consuming and expensive, so it is less economical than repeated measures or independant groups.