Hi Carlos: Pretest's don't have to done all the time. But when they are, They can be quite beneficial for both student and teacher. Comparing first day to last day performance is an interesting analysis to make. Sensing where the class as a whole is generally performing is good information to have when beginning a class, so that time is not wasted and the emphsasi can be adjusted or tweaked in order to maximise the time available. Some teachers will use pretests as a review process prior to "the test that counts". Also, I don't think taking a pretest bothers too many students when they understand their grade is not likely to be affected by the activity. So, they may even try a little harder. That would be a good thing! Regards, Barry