An educational researcher gives the same test to two groups of students, then delivers an instructional intervention to one group, and then gives both groups the same test again. The intervention/treatment group scores much higher this time; the control (non-treatment) group scores essentially the same as the first time. The researcher concludes that barring other factors, the intervention was what raised one group’s scores. What type of validity does this illustrate?

OPTE: 6-12 is part of the Certification Examinations for Oklahoma Educators (CEOE). CEOS include a wide variety (including subject tests) of exams to help prospective and current educators acquire the certification needed to teach in Oklahoma public schools. 

Secondary school teachers in Oklahoma must be qualified to teach grades 6-12. You can prove your qualification for this age range by passing the OPTE: 6-12.