In my previous blog post, I noted that reliability and validity are two essential properties of psychological measurement. Measures of intelligence, personality, vocational interests, and so forth ...

The maturation threat can operate when biological or psychological changes occur within subjects and these changes may account in part or in total for effects discerned in the study. For example, a ...

Internal validity is the extent to which a piece of evidence supports a claim about cause and effect, within the context of a particular study. It is one of the most important properties of scientific ...

The information needed to determine the internal and external validity of an experimental study is discussed. Internal validity is the degree to which a study establishes the cause-and-effect ...