Types of validity and reliability

Internal validity

refers to the cause-and-effect relationship that a study or experiment can demonstrate and whether any notable changes in the dependent variable are as a direct result of the independent variable

External validity

refers to what extent the result of a study can be generalised to other populations, settings, or conditions and whether the results are consistently true beyond what has been studied.

Construct validity

evaluates how well or accurately a study measures, captures, or represents the theory or concept it it trying to assess.

Face validity

subjective evaluation of whether a measure appears to be a logical, reasonable, and appropriate measure of what it is intending to assess (literally thinking or judging something at face value)

Test-retest reliability

evaluates the consistency of a measure by applying it to the same individuals on two separate instances and comparing the results. The results/measure are reliable if they yield similar results both times.

Inter-rater reliability

examines the consistency of measurements when different observers are assessing the same situation. It's about determining the degree of agreement between different observers.

Internal consistency reliability

this assesses the degree to which different items or questions within a measure or study consistently measure the same contract. It is typically calculated using statistical questions