Experimental design Flashcards
matched pairs, independant measures and
What are independent measures?
Each participants takes part in one condition, either in experimental or control group
Example of independent measures?
Group A- does a test with music
participants- 1 2 3 4 5
Group B- does a test w/o music
participants- 6 7 8 9 10
Strengths of independent measures?
-Theirs less material needed (same test being done once by diff p’s)
-No order affects (participants won’t be fatigued)
-Less chance of demand characteristics (p’s less likely to guess the aims)
Limitations of independent groups?
-More p’s needed
-Individual differences- diff p’s in each conditions, comparisons not accurate
Ways to overcome limitations of independent groups?
Random allocations- no researcher influences p’s for groups picked on one by one in a hat
What are repeated measures?
each p’s take part in both (experimental and control group) conditions and performance in each is compared
Strengths of repeated measures?
-no individual differences
-less p’s needed
Limitations of repeated measures?
-order affects
-demand characteristics
-more material needed
Ways to overcome repeated measure limitations?
Counterbalancing- half of p’s to A then B
Other half of p’s do B to A
Example of repeated measures?
Group A- with music
paricipants- 1 2 3 4 5
Group B -w/o music
participants- 1 2 3 4 5
What is matched pairs?
Different p’s in different conditions, but p’s are atched as closley as possible on iq age personality
pretested for variable before experimeny
each pair contributes to one member of control and experimental group so 2 groups are as evenly matched as possible
Example of matched pairs?
Group A- with music
participants- A B C D E
Group B - w/o music
participants- a b c d e
Advantages of matched pairs?
-less chance of individual differences
-no order affects
-less demand characteristics
Limitations of matched pairs?
-more p’s needed
-more materials needed
-time consuming
-matching p’s is difficult
