experimental design

Question 1

how are independent measures conducted?

Answer 1

1. Recruit a group of participants
2. Divide them into two
3. one group does the experimental task with the IV set for condition 1
4. then the second group does condition 2

Measure the DV for each group
Compare the results for the two groups

Question 2

what are the advantages of independent measures?

Answer 2

• There will not be any practice order effects from doing two conditions, because they only do one.
• There will not be any boredom or fatigue effects
• Participants are less likely to guess the aim as they only do one condition, this reduces demand characteristics.

Question 3

what are the disadvantages of independent measures?

Answer 3

• No control of participant variables (e.g. different abilities, one group could be more able than the other).
• You need twice as many participants.

Question 4

how are repeated measures conducted?

Answer 4

Recruit a group of participants
The same set of participants does both condition 1 and 2
compare the results for the 2 conditions

Question 5

what are the advantages of repeated measures?

Answer 5

1. Participants are the same in each condition, so there are no participant variables.
2. You don’t need as many participants.

Question 6

what are the disadvantages of repeated measures?

Answer 6

1. One condition may be easier than another and affect the results.
2. There may be demand characteristics where ppt’s guess
   the aim, which may affect their behaviour, some may purposely perform worse to get the results they think are required

Question 7

what are order effects?

Answer 7

The order of the conditions may affect

performance

Question 8

what are practice effects?

Answer 8

they may do better on the second condition

Question 9

what are boredom and fatigue effects?

Answer 9

they do worse

Question 10

how do we counterbalance repeated measures?

Answer 10

-Reduces order, practice and boredom effects

• Half PPs do condition A then B
• Other half do condition B then A
• Fully counterbalanced: ABBA

Question 11

how do we conduct matched participants?

Answer 11

• Recruit a group of participants
• Find out what sorts of people you have in the group
• Recruit another group that matches them one for one
• one group does condition 1 and the other does condition 2
• Compare the results for the matched pairs

Question 12

what are the advantages of matched pairs?

Answer 12

• This controls some of the participant
  variables.
• Participant’s won’t guess the study aims.

Question 13

what are the disadvantages of matched pairs?

Answer 13

It- Very time consuming to match participants.

- May not control all participant variables.