For further information, see the booklet Assessment for learning (Ref: 0521-2004) from Excellence and enjoyment, learning and teaching in the primary years (Ref:0518-2004) http://www.standards.dfes.gov.uk/primary/publications/learning_and_teaching/1041163/.
Phase 1
Say what the purposes of lists and labels in the classroom are (teacher observation).
Phase 2
Give a complete sentence as a caption for an object or picture (teacher feedback).
Phase 3
Write a caption for an object or picture in a complete sentence with a capital letter and full stop (teacher feedback, self-assessment against agreed checklist).