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 ...

The Massachusetts state Education Department last year commissioned Mathematica Policy Research to do a validity study comparing the Common Core test known as PARCC, created by a federally funded ...

From the perspective of score interpretation, the purpose of testing accommodations is to reduce the dependence of test scores on factors that are irrelevant to the construct that is being assessed.

Of 100 studies published in top-ranking journals in 2008, 75% of social psychology experiments and half of cognitive studies failed the replication test Psychology experiments are failing the ...

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 ...

An approach where the dependent variables are measured before and after an intervention has been delivered. The intervention can either be delivered by the investigator or by others (observational ...