Research method which manipulates
and measures variables to discover
cause and effect
3 Types of
experiment
LABORATORY - Highly controlled conditions,
variable being manipulated by researcher is IV
(Independent variable), change in behaviour
measured by researcher is the DV (dependent
variable)
STRENGTHS
Can control variables
Standardised procedures so easily replicable
Can make
statements
about cause
and effect
WEAKNESSES
Not ecologically valid, artificial, highly
controlled situation, not true to real life
it is not always be possible to
completely control all variables.
There may be confounding
variables affecting the DV
Demand characteristics, if participant
knows they are in an experiment they
may change their behaviour
FIELD - Carried out in
the natural environment,
IV is still manipulated by
researcher
STRENGTHS
Less demand
characterisitics
Ecologically
valid
WEAKNESSES
Harder to
control
variables
could be
many
confounding
varaibles
Ethics - Participants should
give informed consent and be
debriefed afterwards but
difficult to do this in field
experiments
QUASI (NATURAL) - The
IV is not manipulated by
the researcher, it is
naturally occuring
STRENGTHS
Ecologically
valid
WEAKNESSES
Harder to establish
cause & effect, could
be many confounding
variables
3 Experimental
designs
INDEPENDENT MEASURES
- different participants for each
condition
MATCHED PAIRS - different but
similar participants used for each
condition, participants put in
matched pairs based on key
variable
REPEATED
MEASURES - same
participants used in all
conditions