Posttest data should be gathered at a time when students have sufficiently completed an educational experience so as to have engaged and further developed their critical thinking, but not so late in their educational experience that they are not motivated to commit the cognitive energy to give their best effort on the posttest.

Appropriate timing might be five weeks before the end of the academic year when comparing seniors and freshmen, three weeks before the end of the semester when comparing pretest and posttest scores in a 16 week course or  two weeks before the end of the term when comparing pretest and post-test scores in a 10 week course. 

Contact IA educational testing specialists to discuss your project’s assessment design, including the option of using a post-test only design.