I have students complete a preassessment before we begin a unit. Almost all students cannot fill it out completely or receive a 100 % on it. Students should only be using prior knowledge and no research. I then collect these and hold onto them for the rest of the unit. The day before the unit test, i return this worksheet and the students use a different colored pen and complete the worksheet. I like doing this because it allows the students to measure their growth of knowledge they achieved throughout the unit and also helps them realize which topics they should be reviewing for the test.