Different interfaces cause the user to interact in different ways.
This affects how they build up information about the domain they are working in. The counterintuitive finding is that less easy to use interfaces can be beneficial to the domain learning process. Less direct interfaces cause the user to build a more verbalisable and transferable body of knowledge about the domain. The research outlined here is examining this learning process to draw conclusions about where the effect can be most usefully employed. The rationale behind direct manipulation is to allow rapid learning of functionality for beginners and rapid action for expert users.