types of experiments Flashcards
What is a lab experiment?
It takes place in a controlled/artificial environment in which the researcher manipulates the IV and records the effect on the DV.
What are the strengths of a lab experiment?
- Control over EV & CV in which the researcher can ensure the effect on the DV is due to the manipulation of IV. This increases the internal validity of the experiment.
- Replicable due to the high levels of control which ensures no EV’s are introduced if it is repeated
What are the weaknesses of a lab experiment?
-Lacks generalisation as the environment is artificial and not like everyday life which means ppts may behave in unusual ways and lower the external validity.
- demand characteristics are likely
- low mundane realism - tasks may not represent everyday life
What is a field experiment?
The IV is manipulated in a natural setting and DV’s effects are recorded
What are the strengths of a field experiment?
Higher mundane realism due to a more natural setting which may produce more valid and authentic results. Therefore increasing the external validity.
What are the weaknesses of a field experiment?
- loss of control over the CVs and EVs which means it may be difficult to establish information and replication may not be possible
-ethical issues as ppts can’t give consent if they are unaware they are being part of a study which is an invasion of privacy
What is a natural experiment?
The change in the IV naturally happens and the researcher records the effect on the DV (someone or something can cause IV to vary)
What are the strengths of a natural experiment?
- provides the opportunity for research which may not happen for practical or ethical issues
- high external validity as it studies real-world problems and issues
What are the weaknesses of a natural experiment?
- natural events may rarely happen which reduces opportunities for research
- ppts may not be randomly allocated to experimental conditions
- research may only happen in a lab which lacks realism and demand characteristics can be an issue
What is a Quasi experiment?
The IV has not been determined by anyone but it simply exists and can’t be changed which means it is an existing difference in people.
What are the strengths of a quasi experiment?
- more ecological validity
What are the weaknesses of a quasi experiment?
- can’t randomly allocate ppts to conditions which may cause CVs
- IV is not changed by the researcher so we can’t claim the effect on the DV is due to the IV
