Experimental design Flashcards
Define experiment.
A method of testing a hypothesis through manipulating an independent variable and measuring the outcome of the changes.
What is the IV
The variable being manipulated.
What is the DV
The variable being measured
Define independent measures design.
An experimental design where different participants take part in each condition, which will vary depending on the IV.
What are the strengths of an independent measures design?
Participants are less likely to experience fatigue/behavioural effects (Order effects).
If all other extraneous variables are controlled, easier to assume effect of changes in groups are due to IV manipulation.
What are the weaknesses of an independent measures design?
Impossible to control individual differences, which can cause inaccurate results.
Larger sample is required, which may take up time.
Define repeated measures design.
An experimental design where the same participants take place in both conditions.
What are the strengths of a repeated measures design?
Unlikely that results will be affected by individual differences.
Sample required may be smaller.
What are the weaknesses of repeated measures design?
Participants may guess aim of the experiment (demand characteristics)
Order effects may cause inaccurate reflection on behaviour.
Define matched pair designs.
An experimental condition where differing participants take part in each condition, participants in one condition are matched with someone in the other. Can be matched based on age, gender, behaviour etc.
What are the strengths of a matched pair design?
Order effects should not alter the results.
Participants unlikely to guess the aim of the experiment (Less demand characteristics)
What are weaknesses of a matched pair design?
Difficult and time consuming to match pairs,
Variables may alter behaviour despite being matched.
What are order effects?
Where participants have a response to the various variables they take part of e.g tiredness/ restlessness.
What are demand characteristics?
Where participants realise the aim of the experiment and alter their behaviour to match the aim.
