Experiment types

Experiments

Experiments are methods by which the researcher manipulates variables and measures their effects, are widely used in psychology to gather information

Laboratory experiments

Laboratory experiments are carried out in a highly controlled environment. Factors such as noise, lighting and heat can be controlled

Strength of laboratory experiments

Laboratory experiments have high reliability due to the standardised procedure being employed, more likely to get consistent results when tested for consistency

No extraneous variables increases internal validity, the environment is being controlled as well as other variables. Allowing the researcher to establish cause and effect.

Weakness of laboratory experiments

Lab experiments tend to have more demand characteristics, this is because participants know they're taking part in the experiment, with controlled tasks clearly set up in a laboratory, meaning participants might change their behaviour to be more socially acceptable. Therefore lowering internal validity, cause and effect cannot be established.

There is low ecological validity as the experiment is being controlled, therefore not reflecting real- life scenarios and is often artificial, thus lacking mundane realism.

Field experiments

Field experiments are carried out in a real or natural environment. Experimenters may not control the environment but they still control the independent variable.

Strength of field experiments

Field experiments have high ecological validity and task validity. This is because it is carried out in a natural environment so the findings are more applicable to real - life situations

Field experiments have high internal validity as they are less likely to be affected by demand characteristics, because they don't know they're in an experiment, as behaviour is recorded in a natural setting, allowing cause and effect to easily be established.

Weakness of field experiments

Low ethics, no informed consent or right to withdraw. Participants are unlikely to be aware they are in a study, or what the aims of the study are, violating the BPS 2009 Guidelines.

Less control over extraneous variables, therefore low internal validity. The setting is naturally occurring, making it harder to establish cause and effect. Uncontrolled variables in the environment may be affecting the dependent variable too. Therefore lower reliability as the study cannot easily be replicated to test results for consistency.