L7- Experimental designs

Question 1

3 types of experimental design

Answer 1

• independent groups
• repeated measures
• matched pairs

Question 2

randomisation

Answer 2

• use of chance to control effects of bias when deciding order of conditions
• important if using repeated measure design and same participants taking part in 2 diff conditions

Question 3

standardisation

Answer 3

using exactly same formalised procedures and instructions for all participants - improves reliability

Question 4

random allocation

Answer 4

attempt to control participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition or the other

Question 5

independent group design

Answer 5

• diff participants used in each of the conditions
• participants randomly allocated to balance out individual differences

Question 6

advantages of independent groups design

Answer 6

+ no order effects (sequence in which taken part influences performance or behaviour)- diff participants
+ demand characteristics reduced- less chance to guess aim
+participants not lost between conditions (take part in 1only)

Question 7

disadvantages of independent groups design

Answer 7

• more participants needed
  -chance diff results gained between conditions due to individual differences not iv

Question 8

repeated measures design

Answer 8

each participant is tested in all conditions of experiment

Question 9

advantages of repeated measures design

Answer 9

+ no individual differences= more valid
+ less participants needed

Question 10

disadvantages of repeated measures design

Answer 10

• order effects- avoid by counterbalancing (half do A, half do B, swap)
• demand characteristics more likely- guess aim

Question 11

matched pairs design

Answer 11

• diff participants used in all conditions like independent
• participants in 2 groups are matched o characteristics important for study- age, gender e.g. identical twins

Question 12

advantages of matched pairs design

Answer 12

+ less risk of order effects- only take part in 1 condition
+ individual differences less likely to occur

Question 13

disadvantages of matched pairs design

Answer 13

• more participants needed
• matching process is difficult and time consuming- individual differences cannot be completely controlled and removed