experimental designs Flashcards
experimental designs
The overall plan for the participants in the study.
The different ways in which participants can be organised in relation to the experimental conditions.
There are 3 types of experimental design and the experimenter has to decide which one is best for the particular study they are doing.
independent groups
2 completely different groups of people are used.
Weaknesses:
Individual differences between people, called participant variables, can be a problem with this design
The experimenter needs to find twice as many participants using this design.
Strengths:
The participants only know about one condition in the experiment meaning they will be less likely to catch onto what the experiment is about.
They will not suffer from the boredom of having to do both conditions and will not be able to practise and get better the next time.
repeated measures
Only one group of participants is used.
All participants do both conditions.
Weaknesses:
Order effects (issues that arise from the order that the conditions are presented in) can be a problem.
Participants may catch onto what the experiment is about and adjust their behaviour. Additionally, they may get better due to practice.
Strengths:
Lack of participant variables as we are comparing the same person’s performance.
The ideal ‘fair test’ of the effect of the IV.
matched pairs
Two groups of participants are used, but each participant will be matched on some relevant variable to another participant in the other group.
This is to make groups alike as possible.
Weaknesses:
Can be difficult and time consuming to match participants and may not always be obvious which variables are important to match them on.
Strengths:
Very strong design as it solves the problems of both order effects and participant variables.