Experimental Design Flashcards
What is independent groups design?
An experimental design in which each participant takes part in only one of the conditions of the experiment.
What are the strengths of independent groups design?
There are no order effects.
As both conditions can be tested simultaneously, there is a potential saving of time and efforts.
As participants are involved in one condition only, potential investigator effects and demand characteristics are reduced.
What are the limitations of independent groups design?
Participant variables may affect the results. By chance, participants in one group may differ some crucial way to participants in the other.
Participants are only doing one condition, therefore twice as many participants are needed for this design compared to repeated measures.
What is repeated measures design?
An experimental design where each participant takes part in all conditions.
What is counterbalancing?
A strategy for reducing order effects by ensuring that participant variables occur with equal frequency in all conditions of the experiment.
What is randomisation?
The process of using chance to decide the order in which participants experience the experimental or control condition when using a repeated measures design. It is also used to decide the order of the use of stimuli.
What are the strengths of repeated measures design?
Uses fewer participants - get two or more scores per participant which saves time, effort and money. Participant variables are not a concern.
What are the limitations of repeated measures design?
There is a risk of order effects and because of the need to limit these, the design is a complex one.
The cost of a loss of participants is greater since data for both condition is lost compared to one in independent groups design.
What is matched pairs design?
An experimental design where participants in each condition of the experiment are matched according to important variables.
What are the strengths of matched pairs design?
Good control of participants variables. Eliminates order effects.
What are the limitations of matched pairs design?
Matching participants is very difficult.
