At various points throughout Key Stage 2 pupils should be given an opportunity to attempt to write a program with the minimum of teacher input. This program acts as a simple assessment task and allows the opportunity for the pupil to reflect on their own learning in completing a can-do assessment. These tasks might mimic a recently taught task such as setting pupils the challenge to write a knock-knock joke just after completing the Scratch Animation challenge. For older pupils you might ask them to create a different type of game of their own design as a project following the Scratch game challenge. This allows pupils to put into use programming concepts they have just been taught.
Once the task has been completed encourage pupils to screen-shot their programs (being the easiest way to capture evidence) and paste these screen shots into a program such as Word. From here more able students should be able to annotate their work using text boxes and arrows, or you can simply print the screenshots and write over them in coloured pens or pencils.
The grid page for KS2 Programming inside 123SOW includes downloadable can-do assessment sheets which can be used to scaffold reflections. It should be made clear to pupils that not all objectives will be present in all work. It is as important for pupils to recognise that they have NOT included certain aspects in their programs as it is that they can identify correctly the aspects they have included!