Visualizing data is equal parts science and design: it requires the keen intellect of the scientist and keen eye of the artist. Yet this ability is increasingly within reach of everyone: through greater access to information through the Internet, and more powerful technologies in our hands capable of processing larger datasets. With a bit of patience and practice, anyone can learn to create data visuals. Indeed such skills are becoming indispensable for students, journalists, spokespersons, and engaged citizens.
As a science, it requires a deep knowledge of the data and its meaning. You need to know how the data was collected, what it represents, and how to uncover patterns and relationships in information. Data visualization has a long history in scientific communication. Simple forms include pie charts, line graphs, and network diagrams commonly found in journal articles and textbooks. Newer techniques use larger datasets and allow users to interact with data to create their own visualizations “on demand”. For example, the atlas of economic complexity permits users to explore complex patterns of exports and international trade.
As design, data visualization requires an appreciation for how to convey relationships, categories, and magnitude through the creative use of lines, colours, symbols, position and size. Data visuals help tell a story: starting with a compelling problem or question, using data to provide perspective, and giving the reader some insight or solution. Yet creators must respect the limits in datasets. For example, maps of climate change shows bands of colour with projected changes in temperature or precipitation, but are limited by the scarcity of weather observations stations across the developing world.
To inform public policy – Data visualization is beginning to enrich our understanding of the challenges facing society. Evidence-based illustrations, or infographics, help convey complex policy issues and the potential trade-offs in greater depth than long reports or TV commentaries. Many countries now visualize national budgets using “treemapping” technique to subdivide a simple rectangle with the relative size of public spending on such items as healthcare and education. Such visualizations promise to elevate the level of public debate, in parliament, on the streets, and in our homes.