OK, here we go, ready to build a visualization! And the first step is…step back and think. Successful products (and software) begin with well-thought-out designs, and spending time thinking before diving into implementation provides a huge return on the time invested up front.
The very first thing to think about is the goal of your visualization. To be useful, that goal must be defined before the implementation phase has started. The visualization (like any product or communication) must then be designed with that goal in mind.
The goal of your visualization is going to be informed by your own goals and motivations as well as the needs of your reader. A visualization’s goal is usually to satisfy a need for specific information on the part of your reader (an informative visualization, as discussed in Chapter 2). But the goal may also be to change the reader’s opinions or behavior in some way (a persuasive visualization, also covered in Chapter 2).
Examples of goals for visualizations include: to monitor systems, find bargains, compare company performances, select suitable solutions, track populations, tell stories, find specific data points, find outliers, show trends, support arguments, or simply give an overview of the data.
Goals should be stated in terms of the knowledge that can be acquired from the visualization, and should avoid any references to specific content or implementation—don’t box yourself ...