We assessed the external validity of a prediction rule for nonseminomatous testicular cancer patients. The rule was developed to predict the probability of retroperitoneal metastases being benign ...

There is a distinction that one learns about on the first day of a course in psychological research methods. It is the difference between internal and external validity. Internal validity is ...

When investigators think of generalizability, they typically think of extrapolating the results to other patient populations, depending on whether patients were selected for the study by means of ...