Definitions for "Internal validity"
making sure that nothing else besides the independent variable can affect the dependent variable; this is accomplished by controlling all extraneous variables and by randomly assigning people to different experimental conditions
the extent to which changes in a dependent variable can be attributed to one or more independent variables rather than to a confounding variable. (48)
The certainty that experimental interventions did indeed cause the changes observed in the study group; also the control over confounding factors that tend to invalidate the results of an experiment.
" Degree to which a procedure measures what it is supposed to measure" (Sommer & Sommer, 1997, p.362)
Keywords:  inference, quality, top, back, see
See inference quality. Back to the top
the ability to prove a cause:effect relationship.