On August 31st, 1854, a major outbreak of cholera swept through the Soho district of London. This would later be named the ‘Broad Street Outbreak’ after the street near where it occurred, and at the time, physicians in London disagreed on how cholera was spread. Over the next 10 days, this outbreak would result in the deaths of over 500 residents.
The dominant theory was that cholera was transmitted via airborne ‘Miasma’ particles. A physician by the name of John Snow was skeptical of this theory and conducted interviews of residents in the affected areas to learn more. He documented his findings in a dot map, which charted cholera cases by street address. The results of this showed a correlation between infections and water sources used by residents, leading to the discovery of germ-contaminated water being the source of cholera.
Original map by John Snow showing cholera cases in the 1854 London epidemic

Across London, it was discovered that there were much higher rates of cholera in neighborhoods supplied by water drawn from the River Thames. Other neighborhoods, supplied by different sources and filtered water, had lower rates of cholera and few deaths.
For an organization access to clean, reliable data can be as important as clean, reliable water is to a city. Most industries are changing too quickly for leadership to rely on intuition alone. However, as the volume and quantity of data sources increase, keeping track of what data is accurate, timely and relevant becomes exponentially more difficult. One of the key responsibilities of a data governance team is to be aware of what data assets the business is using and to ensure they have access to trustworthy sources.
Map out the sources
One of the most critical functions of a data governance program is understanding where business users go to get their information. Like John Snow’s approach, interviews are often the best route to discovering this. The data governance team should set up some time with key stakeholders from various areas of the business to find out

