External validity is the validity of generalized (causal) inferences in scientific studies, usually based on experiments as experimental validity. In other words, it is the extent to which the results of a study can be generalized to other situations and to other people.
Inferences about cause-effect relationships based on a specific scientific study are said to possess external validity if they may be generalized from the unique and idiosyncratic settings, procedures and participants to other populations and conditions. Causal inferences said to possess high degrees of external validity can reasonably be expected to apply (a) to the target population of the study (i.e. from which the sample was drawn) (also referred to as population validity), and (b) to the universe of other populations (e.g. across time and space).
The most common loss of external validity comes from the fact that experiments using human participants often employ small samples obtained from a single geographic location or with idiosyncratic features (e.g. volunteers). Because of this, one cannot be sure that the conclusions drawn about cause-effect-relationships do actually apply to people in other geographic locations or without these features.
Read more about External Validity: Threats To External Validity, External, Internal, and Ecological Validity, Qualitative Research, External Validity in Experiments, The Basic Dilemma of The Social Psychologist
Other articles related to "external validity, validity":
... The weapons effect succeeds in producing significance in a laboratory setting, but these findings often do not generalize to society ... Therefore, many critics dismiss the weapons effect due to its lack of external validity ...
... is always a trade-off between internal and external validity—that is between having enough control over the situation to ensure that no extraneous variables are influencing the results and to randomly assign ... One way to increase external validity is by conducting field experiments ... The external validity of such an experiment is high because it is taking place in the real world, with real people who are more diverse than a typical university student sample ...
... Experiments are useful in social psychology because they are high in internal validity, meaning that they are free from the influence of confounding or extraneous variables ... the small samples used in controlled experiments are typically low in external validity, or the degree to which the results can be generalized to the larger population ... There is usually a trade-off between experimental control (internal validity) and being able to generalize to the population (external validity) ...
... The study must either have external validity or internal validity ... If the study has external validity then the study's findings have different settings, procedures, and participants ... External validity will also question what types of subjects and conditions in which the same results can be expected to occur ...
Famous quotes containing the words validity and/or external:
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