Can object (instance) diagrams help first year students understand program behaviour

This paper investigates whether first year programming students can be helped to understand program behaviour through the use of Object (Instance) diagrams. Students were introduced to this diagramming technique as a way of visualising program behaviour and then given questions that tested their understanding of object referencing. It appears that drawing their own diagrams is a strategy applied by more successful students. Attempts to encourage all students to use this technique through scaffolding with partially completed diagrams failed however. Weaker students did not appear to find that the partially completed diagrams helped their understanding or go on to use the technique themselves.