Data Services: Data Visualization

Data Visualization

What is Data Visualization?

Data Visualization is an umbrella term that covers information and scientific visualization. This is a general way of discussing anything that converts data sources into a visual representation (like charts, graphs, maps, and sometimes even tables).

Data Visualization can tell stories, answer questions, and can be more readable than just numbers or words alone. Even as early as the mid-1800s, pioneers like Charles Minard and John Snow used infographics and maps to visualize data! Today Data Visualization is used for everything from COVID dashboards, business dashboards, and even pop culture trends.

What Makes a Great Data Visualization?

Know your audience
- What questions will/do they have?
Select the right chart or method for your visualization
- It is ok if the bar chart is the correct choice, don't overcomplicate just because you can!
Keep your patterns predictable.
- Don't let your viewers get lost; it will make it harder to tell your story.
Tell stories with clear color clues.
- Too many colors can cause issues; keep it simple, like blue for cold and red for hot.
Apply text with care
- Unorganized or too much text will just confuse your viewers!
Emphasis on the essential points
- Make size relative to value, either with color, icon, or marker.
Clean your data
- Clean data is happy data. The cleaner your data, the easier it will be for you to make visualizations and for others to understand them!
Be willing to get feedback!
- Have a friend or colleague look over what you have. A second set of eyes always helps!

For more information on what makes a great visualization, check out these resources:

Data Visualization from the 1800's to today

Napoleon March Map - Charles Minard

Charles Minard - In 1869, Minard made this graph showing the losses the French army suffered during Napoleon's invasion of Russia in 1812-1813. The graphic shows how the French army went from a force of around 470,000 men to only 10,000 on their return. The width of the lines indicates the number of soldiers and goes along with a temperature line chart showing how as the temperature fell, so did the soldiers in the army.

Broad Street Cholera Outbreak Map - John Snow

In 1854 Dr. John Snow mapped a cholera outbreak in a London neighborhood. He was looking to find if there was a trend he could see to help a solution as the outbreak killed over 600. Thinking that the answer to what was happening was in the water sources people were using, he created a dot map to show how cholera cases were concentrated around a pump on Broad Street.

This map and his study showed that water provided by one vendor had a cholera mortality rate 14 times that of other vendors! He then removed the handle from the pump! Snow's work helped create the field of epidemiology and public health, but his theories were not accepted until long after his passing. Today the John Snow Society holds a remembrance and a lecture series to promote the life and work of the doctor.