What is data visualization?
Data visualization is the representation of data as media, usually an image but also video, interactable web objects, maps, or even audio. The purpose of data visualization is to make data easier to understand. An image is easier to understand than a table of numbers, especially when the volume of data is very large or the numbers themselves are very large or small, and provides an accessible way to see and understand patterns, outliers, and trends in data.
Like writing, data visualization is a communication skill that can be used in many ways and contexts. Almost everyone will encounter visualizations in work or life and can benefit from an understanding of how they convey messages. If you're interesting in learning more about creating data visualizations, the Leatherby Libraries Data Visualization guide may be of interest.
Creator choices in data viz
Data visualization is part art, part science - the creator makes choices about how to present and emphasize features of the data.These choices include color, position, and other "elements" of the visualization that represent aspects of the data. These features can direct your attention to or away from parts of the data. The creator also decides on axes, labels and scales that can exaggerate or minimize differences.
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.