Mapping Experiences, 3rd Edition

CHAPTER 3

CHAPTER 3. Foundations of Mapping Experiences

The purpose of visualization is insight, not pictures.

—Ben Shneiderman, Readings in Information Visualization

IN THIS CHAPTER

• Framing the mapping effort
• Touchpoints
• Moments of truth
• Value creation

The cause of the great cholera outbreak in London in 1854 was initially unclear. Prior to Louis Pasteur’s germ theory, many thought the disease was in the air. John Snow, a London physician, had a different explanation. He believed cholera was in the water. After microscopic examinations were inconclusive, Snow instead analyzed the spread of cholera to prove his hunch.

To do this, he mapped cholera cases in Soho, London (Figure 3-1). The resulting patterns demonstrated causality: proximity to a certain water pump correlated to cholera cases with high predictability. The decline of cholera is credited to Snow’s recommendation to shut down that pump.

Figure 3-1. John Snow’s map of London during the great cholera outbreak of 1854. The red circle highlights the water pump that was the source of the disease.

Snow’s map contained multiple layers of information—streets, houses with cholera cases, and water pumps—just enough to reveal previously undetected evidence (in this case, the cause of a disease). The approach was simple but effective, and Snow was able to generate a hypothesis based on his map: if the city shut down ...