Catherine from visualizingeconomics.com has written an interesting article about the roles in data visualization. The posts that your reading right now are my thoughts about the diagram she created and how I would alter the stages in the process. I recommend reading her article first, as my answer is based on her thoughts. But here’s the diagram that illustrates well the basic idea:
For highly complex visualizations it is important in my opinion to combine the visual representation with the interaction model early on. If we think that visual representation often starts with rough sketches it is my believe that interactivity should be treated the same way. Creating interactive mock-ups helps getting a better understanding on how the audience later on will use an interactive visualization.
The two fields strongly interact with each other and by planing the interactions together with the visuals the designer can find solutions to reduce information overload and to grant access to the needed information.
So, my suggestion would be to switch 6.refine with 7.interact. This gives us time and space to create the visualization and the interaction model, as well as to refine both parts in perspective to each other.