Lecture 2 | Motivation
Max Pellert
IS 616: Large Scale Data Analysis and Visualization
Data Visualization?
Why do you need that?
Visual communication is important in all areas: industry, science, …
But also for yourself, to learn and to remember
In the context of science especially: to get new insights
Especially important for very large data sets
But keep in mind: pure eyeballing can also mislead (connected to the problem of induction, “reasoning after the facts”)
A tale of epidemics…
The Cholera Epidemic in London, 1854
Cholera broke out in the Broad Street area of central London on the evening of August 31, 1854
Causes and possible interventions were unclear
“Miasma theory” (“pollution”) held that “bad air” or “night air” was responsible
Miasma could eminate from rotting organic matter, for example from burying grounds of plague victims from two centuries earlier
The Cholera Epidemic in London, 1854
John Snow who investigated earlier epidemics had a different theory of the causes
He wasn’t successful in verifying his suspicions directly
So he tried an indirect strategy to find the causes: Data Visualization
He obtained a list of 83 deaths from cholera (including the addresses of the victims)
And plotted them on the map of the part of London that was affected by Cholera
Intervention
John Snow had the handle of the pump removed
