Dr. Dumbledore developed a brand new technique that is designed to reduce procrastination in academic endeavors. He recruits 20 students and has them record the amount of time (in minutes) they spent procrastinating for a week (he used this measure as a pretest measure of procrastination). All of the students were then asked to attend a workshop in which they are taught Dr. Dumbledore's new technique (a specific warm-up exercise that is designed to reduce procrastination). After completing the workshop, students were again asked to record the amount time spent procrastinating for a week (he used this measure as a posttest measure of procrastination). The difference between procrastination in the pretest and posttest (i.e., pretest score - posttest score = difference) was examined.