I love August–a deliciously quiet month when I procrastinate to my heart’s content and I savor the last days of summer.
So, when a friend sent me the following “Pie Chart of Procrastination” I marveled at the timeliness of her message while enjoying a really great laugh.
August is also the time when I slow down (hammock swinging slowly). I revisit my library of texts about data and data visualization and I review new work on the subject. This week I returned to a terrific book by Connie Malamed, “Visual Language for Designers: Principles for Creating Graphics that People Understand.”
Malamed’s Principle 4–Make the Abstract Concrete is a great refresher about the importance and power of data visualization to make abstract ideas and concepts concrete. She writes:
“We gain enormous insights from representing information in a visual form. From ancient maps to interactive visualizations, the graphical depiction of data and concepts has created new ways of seeing things and new approaches to solving problems. Two significant examples from the early history of graphs exemplify this point. In 1854, Dr. John Snow visually plotted where deaths were occurring from a cholera epidemic in London….and during the Crimean War; Florence Nightingale invented a new type of statistical chart proving that British soldiers were dying at a much higher rate from preventable diseases than from the wounds of battle.”
Let’s look at how each of these is a terrific example of conveying data visually to inform and compel right actions by health officials.
The notorious wellhead pump that supplied the cholera-infected water that took the lives of 600 Londoners in September 1854 was identified as a result of Dr. Snow’s work. During that swift and deadly epidemic, Dr. John Snow did his magnificent detective work (founding modern epidemiology), discovered the cause of the epidemic, and induced the Parish Council to remove the handle of the Broad Street pump, which ended the epidemic.
I have simplified it, but the great contribution of John Snow was to identify the public health policy that ended cholera epidemics in England: keep the drinking water clean and free of sewage–and he did it with a visual display of data.
By simply plotting individual deaths on a map, Snow was able to locate the contaminated source of water and more important, he was able to convincingly impart the information to authorities and compel them to act.
Snow’s work also laid the foundation for modern day surveillance programs, where disease outbreak and trending data are often communicated using geospatial displays, upon which we rely, to monitor and protect the health of communities throughout the world.
Through her work as a nurse in the Crimean War, Florence Nightingale was a pioneer in establishing the importance of sanitation in hospitals. She meticulously gathered data on relating death tolls in hospitals to cleanliness, and invented the Polar-Area or Coxcomb diagram to dramatize the extent of needless deaths in British military hospitals during the Crimean War.
The area of each colored wedge, measured from the center, is proportional to the statistic being represented. Blue wedges represent deaths from “preventable” diseases (e.g. cholera, typhus), pink wedges deaths from wounds and gray wedges deaths from all other causes.
Like Snow, Nightingale was able to visually represent the magnitude of preventable disease among soldiers and her petition to improve sanitation conditions was a success.
Although sometimes likened to a pie chart, I find that simplistic comparison to be unfair to the beauty of Nightingale’s work. In part a stacked bar graph and in part a timeline that plots the months of the year clockwise thereby imparting a feeling of motion, I view Nightingale’s diagram as a brilliant and beautiful work of art that saved thousands of soldiers’ lives.
Charts, graphs, diagrams, visualizations, maps and timelines are referred to by many names, but regardless of their name and form their purpose is the same–to make abstract ideas and concepts concrete.
And where the visual communication of this data was once the domain of statisticians, cartographers and groundbreaking thinkers like Snow and Nightingale, all of us are now called upon to produce data presentations for quality improvement projects, research publications and patient education publications (to name just a few).
And so my message today is very simple…I encourage you to follow my lead and take a bit of time to consider the power of data visualization and to learn more about the best practices. It is as simple as opening a book and finding an open hammock.