This paper reports the findings of an empirical investigation, which set out to test a set of rainbow essay exercises. The rainbow diagrams are pictorial representations of formal graphs that are derived automatically from student essays. They were designed to allow students to discover how key concepts in a well written essay are connected together. The students would then be able to compare a rainbow diagram of their own essay with a good essay and make changes to it before submission to their tutor. However a trail was undertaken with academics, teaching and learning staff, doctoral students at the Open University of Catalonia and the Open University UK, before implementation into the web application known as Open Essayist. All the participants from each University completed the exercise correctly. This was a surprising finding as we expected participants to experience some difficulties, as previous visual representations we piloted. All the participants remarked that they had learnt a lot about the structure of good essays and more importantly how clear the role of the conclusion played in a well-constructed essay. This type of representation made this explicit and they would be able to see quickly if a second draft had improved. The users also mentioned that the rainbow diagram representations could be used as a
generic essay feedback tool. It could be used across subject domains, a hypothesis worthy of further investigation
