L4: Experimental Methods 2

Question 1

Outline within-subjects design

Answer 1

AKA repeated measures
-all participants receive all levels of the independent variable

-solve order effects by counter balancing (ABBA)

Question 2

Outline between-subjects design

Answer 2

-different groups of participants receive different levels of an independent variable

Question 3

Outline quasi-experiments

Answer 3

One or more independent variables are selected (not manipulated)

E.g “effect of education on memory skills”

• quasi-independent variable: education (do they have a degree or not)
• dependent variable: scores in memory test

-participants are not randomly assigned to the levels of the independent variable (education) which leads to more confounding variables which cannot be removed (are people with better memories more likely to go to university?)

Question 4

Name some different sampling types (only need 3 on this case)

Answer 4

• random sample
• stratified sample
• quota sample

Question 5

Difference between stratified sample and quota sample

Answer 5

Stratified: random selection in each sub-group basically

Quota: using pre determined percentages of each sub group to determine the percentage of that certain sub group in the sample