experimental design

Question 1

define independent design

Answer 1

where each participant only takes part in one condition of the IV

Question 2

advantages of independent design

Answer 2

+ Order effects cannot be observed, as no participants will be used in more than one condition.

+ Data collection will be less time-consuming if all conditions of the experiment can be conducted simultaneously.

Question 3

disadvantages of independent design

Answer 3

• Different participants need to be recruited for each condition, which can be difficult and expensive.
• There is a risk of participant variables (individual differences between participants) affecting the results between conditions, rather than solely manipulation of the independent variable.

Question 4

define repeated measures design

Answer 4

An experimental design where each participant takes part in both/all conditions of the IV

Question 5

advantages of repeated measures design

Answer 5

+ The results will not be subject to participant variables = putting more confidence in dependent variable changes being solely due to manipulated independent variable.

+ As the same participants are used [at least] twice, extra participants do not need to be recruited. = less expensive and time-consuming

Question 6

disadvantages of repeated measures design
how can the risk be reduced

Answer 6

• There is a risk of observing order effects (e.g. practice/fatigue effects, or demand characteristics),
• but this risk is reduced by counterbalancing (i.e. controlling the order of variables so that each order combination occurs the same number of times, e.g. half of the participants partake in condition A followed by B, whereas the other half partake in B followed by A).
• If a participant drops out, data will be lost from all conditions of the experiment rather than one.

Question 7

design matched pairs design

Answer 7

An experimental design where pairs of participants are matched on important characteristics and one member is allocated to each condition of the IV

Question 8

advantages of matched pairs design

Answer 8

• Order effects will not be observed as participants only take part in one condition.
• The tailored participant-matching process reduces the risk of participant variables (individual differences) affecting results between conditions.

Question 9

disadvantages of matched pairs design

Answer 9

• Different participants need to be recruited for each condition, which is difficult and expensive.
• Matching is a more complex process, and it will always be very difficult to match participants identically.