types of experiment Flashcards
lab experiment
takes place within a controlled environment. researcher manipulates the IV and records the effect on the DV.
field experiment
the IV is manipulated in a natural setting and effect on DV recorded.
natural experiment
change in IV not brought about by researcher. (pre-existing IV). researcher records effect on DV.
Quasi experiment
an IV that is based on an existing difference between people, not manipulated by researcher.
e.g. age, gender
lab- strengths
- control over extraneous variables, high internal validity.
- levels of control mean replication more possible. can confirm validity of findings.
lab- weaknesses
- may lack generalisability, artificial setting so behaviour may be diff to outside research setting. low external validity.
- demand characteristics. in-genuine behaviour.
- low mundane realism. tasks may not represent IRL experience.
field- strengths
- higher mundane realism. environment more natural.
- less demand characteristics.
- more authentic behaviour. high external validity.
field- weaknesses
- loss of control over extraneous variables. lower internal validity. precise replication less possible.
- ethical issues. if unaware cannot consent to being studied.
natural- strengths
- provide opportunities for research that may not otherwise be undertaken for practical/ethical reasons (e.g. institutionalised Romanian orphans)
- high external validity. study of real-life issues and problems as they happen.
natural- weaknesses
- reduced research opportunities, events occur rarely. limits generalisability of findings.
- participants may not be randomly allocated to experimental conditions. lower internal validity. e.g. Romanian orphans IV age of adoption, but lots of other individual differences between them.
quasi- strengths
often carried out under controlled conditions and therefore share strengths of a lab experiment
quasi- limitations
cannot randomly allocate participants to conditions and therefore there may be confounding variables.
