RM - Laboratory and field experiments Flashcards
What is a field experiment?
A controlled experiment conducted outside a laboratory. The IV is manipulated by the experimenter, but participants are usually unaware that they are being studied so behaviour is more natural and they are less likely to respond to cues from the experimenter.
Do field experiments have high or low internal validity and why?
Lower as it is more difficult to control extraneous and confounding variables.
Do field experiments have high or low external validity and why?
Higher as there is greater mundane realism.
What is a laboratory experiment?
An experiment carried out in a controlled setting where the IV is manipulated and the DV is measured.
Do laboratory experiments have high or low internal validity and why?
High because good control over all variables is possible.
Do laboratory experiments have high or low external validity and why?
Low ecological validity as participants are aware they are being studied and also the tasks involved tend to be more artificial.
What are the strengths of lab experiments?
High internal validity as extraneous variables can be controlled meaning that we can be confident that any observed change in the DV is due to the IV.
Easily replicated, demonstrating external validity.
What are the limitations of lab experiments?
Participants usually aware that their behaviour is being studied leading to them searching for cues about the aims of the experiment and may affect the participant’s behaviour, reducing ‘realness’ (ecological validity). Artificial. Demand characteristics.
The IV or DV may be operationalised in such a way that it doesn’t represent everyday experiences (low in mundane realism) leading to low ecological validity.
Low ecological validity can also be explained in terms of setting as participants may feel uncomfortable in an unknown and artificial environment meaning that they may not behave as they usually would.
What are the strengths of field experiments?
Participants unlikely to be aware that their behaviour is being studied meaning that they don’t respond to demand characteristics and therefore their behaviour may be more ‘natural’. Less artificial.
Takes place in a more natural setting so participants may be more relaxed (e.g. a classroom at school).
Higher mundane realism and higher ecological validity.
What are the limitations of field experiments?
Many the same as lab experiments e.g. the IV in the field experiment may lack mundane realism and therefore field experiments are not necessarily more like everyday life than lab experiments.
More difficult to control extraneous variables reducing internal validity.
Major ethical issue - Participants don’t know that they are being studied so it is difficult to debrief them raising ethical issues with manipulating and recording their behaviour.
More time-consuming and thus more expensive.
