The Essences of Visualization & Simplicity

The defining challenge of data visualization is projecting high dimensional data onto a low dimensional canvas. (As a rule, one should never do the reverse: visualize more dimensions than what already exist in the data)

– Michael E. Driscoll ( Dataspora Blog )
This holds for several other things too. You should never try and add something ( words, slides, features, etc… ) when it’s not required.