types of experiment Flashcards
what is a lab experiment
- conducted in highly controlled environments
- researcher has high levels of control over variables
- the experimenter will control environmental factors (eg noise, temp) as well as the experience each ppt has through standardised procedures
strength of laboratory experiments
- easy to establish cause and effect relationships bet changes to iv and observed difference in dv bc all other variables apart from iv and dv are controlled
- there is high control over confounding variables and extraneous variables so can be certain observed change in dv is due to iv hence high internal validity
- lab studies are easily replicated due to use of standardised procedures
weaknesses of labatory experiments
- low external validity, findings from lab studies cannot be easily generalised to the real world
- tasks lack mundane realism artifical tasks dont reflect those of real life
- ppts change their beh as they are away theyre in a study via demand characteristcs change beh to match aim (unnatural beh*
what is a field experiment
experiment conducted in natural, everyday environment
strength of field experiment
-higher ecological validity, ppts should behave more naturally in normal environment so results can be generalised to other natural settings
- more mundane realism, tasks resemble that of the real world
- if ppts are unaware they’re taking part in a study they will not show demand characteristics
weaknesses of field experiments
- lack of control of extraneous variables that could be influencing the DV so hard to establish cause and effect relationships bet IV and DV
- and thus hard to replicate
- ethical issues if ppts unaware theyre being studied, issues w consent
what is a natural experiment
researcher has no control over IV - it occurs naturally eg a natural disaster
strengths of a natural experiment
- allow research into areas that couldnt be conducted in controlled environments due to ethical or cost reasons
- high external validity as involves real world beh as they happen free of demand characteristics
limitations of a natural experiment
- events have already happened or will happen regardless of the researcher so no control over extraneous variables hard to establish cause and effect relationship
- often involve the study of rare events which cannot be replicated exactly to test for reliability
what is quasi experiment
- IV is pre existing and cannot be manipulated eg gender or age
- ppt cannot be randomised to different conditions
strength of quasi experiments
- only way to experimentally study factors that are pre existing characteristics of ppt
- often carried out under controlled conditions so have ability to replicate
weakness of quasi experiment
- cannot randomly allocate ppts to conditions so issue of confounding variables
- cannot establish cause and effect between IV and DV
