<p>In order for vocational teachers to figure out what their students need to learn about a specific vocational content, students should be given opportunities to experience variation, as well as express their knowledge and understanding of the specific content to be learned. This study examines the teaching and learning processes that are made possible when teachers work systematically with teaching based on educational theories that highlight dialogue and variation in interaction with students. The teaching theory CAVTA (Conversation Analysis and Variation Theory Approach) has been systematically implemented by vocational teachers aiming to increase vocational students’ learning by giving them opportunities to express their understanding of teaching content in interaction. In the teaching session selected for a detailed analysis in this article, the teacher systematically created a teaching situation in which a student worked in different working heights and compared them with each other, aiming to highlight working height as a critical aspect of working in an ergonomically sustainable working position when changing brake pads on a passenger car. The results show that it is possible for the teacher and the student to make visible, concretise, and specify the learning content to be learned in interaction through the simultaneous use of semiotic resources and contrast as teaching tools based on CAVTA. This enables the student to experience variation, something that is highlighted in variation theory as a necessary condition for learning.</p>