Teachers in a local school district are given a test of computer literacy (scores of 0-100 with 100 being perfect). Then during the school year they have monthly in-service programs designed to improve literacy. Their computer knowledge is assessed again at the end of the school year. Their average pretest score is 40 and their average posttest score is 80. Teachers in a comparable school district aren't given the training but they do get the pretest and posttest. This study uses a _____________ design.