Experiments Flashcards
What is an IV?
It is the ‘independent variable’ and is manipulated by the experimenter
What is a DV?
Is it the ‘dependent variable’ and is measured by the experimenter
Why do experimenters control extraneous variables?
To demonstrate a causal relationship / to show that changes in the DV are caused by the manipulation of the IV
Name three types of experiment
Laboratory, field and natural experiments
Which type of experiment makes use of existing IV’s (i.e. they cannot be manipulated)
Natural experiment
Which type of experiment does not randomly allocate participants to conditions?
Natural experiment
Which type of experiment does not allow causal conclusions to be drawn?
Natural experiment
Sometimes participants are not aware that they are taking part in a study - what can this reduce?
Experimenter effects
The way the IV is operationalised may convey the experimental hypothesis to participants - what can this lead to?
Demand characteristics
Which type of experiment has the highest control over extraneous variables?
Lab experiment
Which type of experiment is the most easily replicated?
Lab experiment
Which type of experiment tends to be high in internal validity?
Lab experiment
Which type of experiment tends to be low in external validity?
Lab experiment
Which type of experiment tends to be low in external validity?
Lab experiment
Apart from the level of control, what else can reduce internal validity?
Experimenter effects and demand characteristics
What is internal validity?
Concerns what goes on inside the study - Are we accurately measuring what we intend to measure?
What is external validity?
Concerns things outside the study - The extent to which results can be generalised to other situations and people
What is external validity?
Concerns things outside the study - The extent to which results can be generalised to other situations and people
What is reliability?
The ability to repeat a study and obtain the same results. It is essential that all conditions remain the same.
Name three experimental designs
Repeated measures, independent groups and matched pairs
What is a repeated measures design?
When each participant is tested on all of the IV’s
What is an independent groups design?
Separate groups for each IV
What is a matched pairs design?
Participants in each independent group are matched on key variables (e.g. age and IQ)
