Natural and Quasi-experiments Flashcards
what are natural experiments?
a method where the experimenter has not manipulated the IV directly
The IV would vary regardless
The researcher records the effects of the IV on the DV
Experiments often involve the manipulation of the IV and random allocation to conditions by the experimenter - this does not apply in a natural experiment
casual conclusions can be tentatively drawn
when are natural experiments used?
when it is unethical to manipulate the IV therefore it is said that it varies naturally
Name an example of a natural experiment study?
effects of institutionalisation (Romanian orphans)
the IV in this study is adoption either before or after six months
what is a quasi-experiment?
contains a naturally occurring IV
the IV does not vary
The researcher records the effect of the quasi-IV on a DV
The lack of manipulation of the IV and the lack of random allocation means conclusions can be tentatively drawn.
the IV is a difference between people that exists
Name a quasi-experiment study
Sheridan and King 1972 tested men and women’s obedience by participants to give genuine electric shocks of increasing strength to a puppy
54% of males complied
100% of women complied
The IV was gender which could not be manipulated
strengths of natural experiments
enables psychologists to study ‘real problems’ such as the effects of a disaster on health (increased mundane realism and ecological validity)
Allows research where IV can’t be manipulated for ethical or practical reasons
weakness of natural experiments
random allocation is not possible so therefore there may be many confounding variables which is a threat to internal validity
cannot establish casual relationships because IV is not directly manipulated
strengths of quasi-experiments
allows comparison between types of people
weakness of quasi-experiments
participants are aware of being studied which creates demand characteristics which reduces internal validity
DV may be artificial reducing mundane realism
