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 ...

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 ...