The lesson plenary is an opportunity for the teacher to round off and summarise the lesson, to underline what teaching has accomplished. It helps pupils to focus on the most important rather than the most recent points that they have learned and the progress they have made. It should aim to refocus pupils on the teaching objectives that have featured in the lesson. It is also a time to look back and look forward and to relate work in the lesson to other work. For the teacher, the plenary is an opportunity to assess learning and plan accordingly.
Plenaries are also useful part way through a lesson: staging posts when the teacher draws the class together, crystallises understanding and directs the class to the next phase of work.
Plenaries will vary in length, two minutes on one day, 20 minutes on another, depending on the style and format of what the teacher has planned.