Experimental Design Flashcards
What are independent group designs
When participants are allocated to different groups where each group represents one experimental condition
-This means that all ppts experinece 1 level of the IV only
What are repeated measures
All participants take part in all conditions of the experimental condition
What are matched pairs design
Pairs of participants are first matched on some variables that may affect the DV.
Then one member of the pair is assigned to condition A and the other to Condition B
What is random allocation
An attempt to control for participant variables in an indepednt groups design which ensures that each participant has the same chance of being in one condition as any other
What is counterbalancing
An attempt to control for the effects of order in a reapted measure design half the participnats experinece the condiitons in one order and the other half in the opposite order
What are experimental designs
The different ways in whcih the testing on participants can be organised in relation to the experimental conditions
What is the issue with a repeted mesure design
When ppts are tested more than once and experinece all conditions of the experiment there is an increased likelihood they will become aware of the aims of the stud
Weakness of independent group
The participants who occupy the different groups are not the same
-Any differences found may be down to indiviudla differences
-To deal with this random allocation is used
-Less economical than repeated measures
Strengths of indepndent group
-Order effects are not a problem
-Ppts are less likely to guess the aims
Strength of repeated measure
Particpants performance may improve through the effects of practice
-Participant variables are controlled and fewer ppts needed
Weakness of repeated measure
Each participant has to do at least two tasks and the order of these tasks may be significant-ie order effects–>COuld also arrise due to boredom or fatgue
–>might create deterioration in performance on the second task
-Demand charcteristicstend to be a feature of this design
Strengths and weakness of matched pair design
Ppts only take part in a single condition so order effects and deman charcteristcs are less of a problem
Matching may be time conusming and expensive
less economical
