P2 Research Methods - Experimental Designs

Question 1

What is experimental design?

Answer 1

This refers to how participants can be arranged in experiments.
There are three different types: independent groups/matched pairs/repeated measures

Question 2

What is independent groups?

Answer 2

They are totally separate each group experience one level of the IV

Question 3

What is repeated measures?

Answer 3

Both experience both levels of the IV

Question 4

What is matched pairs?

Answer 4

Participants are selected depending on a characteristic which is relevant to the study (which could directly impact on the DV) like the athletic capability, intelligence. age, personality to control participant variables.

Question 5

What is counterbalancing?

Answer 5

A technique used in repeated measures design to overcome order effects that come with practice and to ensure all conditions are completed first and second in equal amounts.

Question 6

What are strengths of independent groups?

Answer 6

1. Increased external validity
   - More participants are used
2. Reduces demand characteristics
   - If participants don’t complete the same experiment twice, they might not guess the purpose of the experiment and won’t change their behaviour
3. Less time consuming

Question 7

What are limitations of independent groups?

Answer 7

1. The researcher cannot control the effects of participant variables (different abilities or characteristics)
2. Needs more participants

Question 8

What are ways to deal with the limitations of independent groups?

Answer 8

1. Randomly allocate participants to conditions

This can be done by putting names in a hat and drawing out names so that every person goes in group A

Question 9

What are strengths of matched pairs?

Answer 9

1. Avoids order affects
   - No practice effects as participants only partake in one condition
2. Reduces the influence of confounding variables

Question 10

What are limitations of matched pairs?

Answer 10

1. Very time consuming and difficult to match participants on key variables
2. It is not possible to control all participants variables

Question 11

What are ways of dealing with limitations of matched pairs?

Answer 11

1. Restrict the number of variables to match on to make it easier
2. Conduct a pilot study to consider key variables that might be important when matching

Question 12

What are strengths of repeated measures?

Answer 12

1. Helps to keep the validity of the results higher while still allowing small groups
2. The experiment will be more efficient

Question 13

What are limitations of repeated measures?

Answer 13

1. The order of the conditions may affect performance
2. When participants do the second test they may guess the purpose of the experiment which may affect their behaviour

Question 14

What are ways of dealing with limitations of repeated measures?

Answer 14

1. Researchers may use two different tests to reduce a practice effect
2. Counterbalancing (participant sample is divided in half with one half completing the two conditions in one order and the other completing the conditions in reverse order