The document discusses the importance of knowing what students already know about a topic (K), what the teacher wants them to learn (W), and what they should have learned by the end of a unit (L). As an example, for a unit on work contracts and salaries, the teacher expects students to already know some concepts about these topics. They want students to learn specifically about workers' rights and duties and labor regulations. By the end of the unit, students should have learned about various topics related to employment, labor laws, contracts, and salaries.