experimantal designs

Question 1

what is an experimental design

Answer 1

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

Question 2

what is independent group design

Answer 2

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

Question 3

what is repeated measures

Answer 3

all participants take part in all conditions of the experiment

Question 4

what is matched pairs design

Answer 4

pairs of participants are first matched on some variable that may affect the DV. then one member of the pair is assigned to each condition

Question 5

what is random allocation

Answer 5

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

Question 6

what is conterbalancing

Answer 6

an attempt to control for order effects in a repeated measure design. half the participants experience the one condition in one order and the other half in the opposite order

Question 7

evaluation independent group

Answer 7

1. limitation
   - participants are not the same in each condition
   - mean difference between groups on the DV mat be due to participants variables rather than the effect of the IV
   - differences may act as confounding variables reducing the validity
   - use random allocation to solve this
2. more economical
   - participation only has to do each condition once
   - participants are less likely to guess aims as there is no order effect

Question 8

evaluation of repeated measures

Answer 8

1. less economic
   - each participant has to do each condition
   - order of tasks may be important
   - counterbalancing used to fix this
2. participant variables are controlled

Question 9

evaluation of matched pairs

Answer 9

1. only take part in one study to order effects and demand characteristic less of a problem
2. time consuming and expensive