Instruction can move forward when classroom evaluations, based on the use of assessments, show that students have learned what they should (Gage & Berliner, 1988). For example, if a classroom teacher requires students to write two persuasive essays on a final exam and they perform well on both essays, then the teacher can reasonably infer that students are capable writers of persuasive essays (Popham, 2001). Remedial instruction is required if classroom evaluation reveals that some or all of the students have not acquired the skills that were taught. In some cases, evaluation indicates that the entire instructional sequence must be started anew.