After last lesson, I felt that interactive visual representation is not just the combination of text, graph, picture, and animation... etc. It seems a story to present what you want to express to your audience by particular purpose. Let's take the Giant Squid task in the class. When we justified which poster is the best, we considered which is most easy for audience to understand and receive the critical information. Of course, different people have different interpretation, that's why, we have different reasons to support our choices.

I agree with Daniel said, we should understand the information and knowledge before designing the visual, but also we should know what the purpose is. If you want your students to answer a set of questions regarding the poster, you should include the information in some way. If you want to let user know the direction, the floor plan should include all the critical locations.