5.3 Datasets
All data came from the United Nations Common Database (http://unstats.un.org/unsd/cdb/) which provides historical data by country.
We downloaded various tables for approximately 270 countries for data from 1975 through 2000.
The tasks, which will be described in the next section,
were inspired by questions addressed by Hans Rosling in his TED conference presentations [16][17].
In order to control the time for each task, we pared down the data to two study datasets, one with 80 countries and one with 18.
These were chosen so that overall trends in the smaller datasets matched overall trends in the full dataset.