What are threats to external validity?
There are seven threats to external validity: selection bias, history, experimenter effect, Hawthorne effect, testing effect, aptitude-treatment and situation effect..
How do you deal with threats to internal validity?
Internal ValidityKeep an eye out for this if there are multiple observation/test points in your study.Go for consistency. Instrumentation threats can be reduced or eliminated by making every effort to maintain consistency at each observation point.
Which of the following threatens the internal validity of an experiment?
The degree of control exerted over potential extraneous variables determines the level of internal validity. … Eight threats to internal validity have been defined: history, maturation, testing, instrumentation, regression, selection, experimental mortality, and an interaction of threats.
What is an example of external validity?
For example, extraneous variables may be competing with the independent variable to explain the study outcome. Some specific examples of threats to external validity: … In some experiments, pretests may influence the outcome. A pretest might clue the subjects in about the ways they are expected to answer or behave.
What is the difference between internal and external validity?
Internal validity refers to the degree of confidence that the causal relationship being tested is trustworthy and not influenced by other factors or variables. External validity refers to the extent to which results from a study can be applied (generalized) to other situations, groups or events.