Types of Experiments

• takes place in a controlled environment
• the experimenter can test the effects of the IV and DV

ADVANTAGES

• Researcher has control over variables, allowing precision to be achieved

• Researcher can establish cause and effect relationships between IV and DV

• Confounding variables are eliminated or held constant, therefore it has internal validity

DISADVANTAGES

• Demand characteristics, pps may try and make sense of the experiment and behave in a way to please the examiner

• Due to the controlled nature of labs, the experiment may become artificial and low in mundane realism

• conducted in normal social situations
• researcher still manipulates IV and measures DV but has less control
• Hofling et al (1966) - obedient nurses

ADVANTAGES

• high ecological validity - true behaviours shown, generalised to real world

• reduced demand characteristics, pps do not know they are taking part

• pps less influenced by investigator effects

DISADVANTAGES

• difficult to control all variables which could affect pps behaviour

• no informed consent, pps are decieved

• IV occurs naturally, experimenter records effect of DV
• After the eruption of St Helens, USA (1980) - increase in stress-related illnesses, diagnosis in mental disorders and death rate

ADVANTAGES

• Realism - real-life events

• Reduced demand characteristics - experimenter is usually not present when event occurs and pps usually don't know their behaviour is being studied

DISADVANTAGES

• Lack of control - experimenter has no control over variables

• Difficult to generalise