Is Dijkstra's Algorithm Coming First?

The model coming first is something that I've found has been really effective and helpful in teaching kind of multi-step problem solving. Harry, can you give us a little bit of an overview of the idea of an exit ticket? How do we tell if students have understood the main point of the lesson? What are some ways to make your course more responsive so it's not just about being able to say 'yes' or 'no' all the time when they're trying to get things done but also helping them understand what needs to be achieved.