Integrate Words, Numbers and Images. This means avoiding references for figures and examples, which are physically removed from the flow of the text. Also information for comparison should be put side by side. That is, within the eye span, not stacked in time on subsequent pages 5. Effectiveness of Visual Design depends upon the Quality, Relevance and Integrity of the Content.
Good design is clear thinking made visible.
Tufte shows a book by Galileo published in 1613, which reported the discovery of sunspots and the rings of Saturn for the first time. Galileo wrote in Italian, not Latin, because he wanted to reach a wider audience than the scientific elite. His tone of writing is wide-eyed, straightforward, undiplomatic, sardonic and sounds a lot like the modern voice of Richard Feynman. The report of the discovery of sunspots has a simple drawing of the sun on each page to show daily observations. From these observations he learned that the sun was rotating as the spots moved across the page and changed apparent shape at the edges due to foreshortening.