It was 1854 and London was experiencing a cholera outbreak. The theory at the time was that the disease was spread by "bad air". This explanation didn't sit well with Dr. John Snow, who took it upon himself to hit the pavement and figure out what was happening. By talking to people in the affected neighbourhood and plotting infections on a map, he found that the disease was clustered around the Broad Street water pump.
In doing his homework and finding out how people lived and moved about, he was one of the first to drastically reduce the cholera outbreak by pinpointing the real problem — the pump. Without challenging assumptions and creating informed and actionable research, we would be fixed to a harmful status quo — bad air.