There are many different variations on these "five steps", but they share a general approach to investigating a visualization and understanding it.
1. Read the title and any guide to reading the visualization provided by the creator. What is the subject of the visualization, and what is being displayed? Is it clear where the data being presented comes from?
2. Figure out what is being measured and compared. Look for axes labels, units, and legends. What is being measured, and how is it being represented? Do the units and the scale of the axes make sense? Are the axes shifted or manipulated in any way?
3. What is the chart creator trying to draw your attention to? Is anything highlighted, bolded, or annotated? Is color used to represent information, and if so, what is the purpose of the chosen colors?
4. What pattern or trend is the chart displaying? Is there any clear average or any notable exceptions?
5. Try to summarize or restate the message of the visualization in your own words. If it's not clear, go through the steps again and note what you've noticed going over the graph a second time.
