The article addresses clarity and coherence of lesson goals as a scaffold for student learning. In 13 physics classes video recordings of the introductory lesson of two topics were rated with respect to clarity and coherence of the lesson structure. HLM analyses showed a positive effect of classes with high goal clarity and coherence on the students' reports on supportive learning conditions, self-determined learning motivation and organising learning activities. Over the course of a school year high goal clarity and coherence resulted in a positive competence development. No effect was found for individual interest development.