The President’s Corner in the May 2017 issue of Amstat News, the monthly newsletter of the American Statistical Association (“ASA”), features the interesting exposition by environmental statistician and President of the ASA, Barry Nussbaum, called “Bigger isn’t always better when it comes to data.” Key paragraph:

Notice a subtle nuance here. Normally, you have a population and you sample elements from the population. Here, we really didn’t know if the vehicle’s emissions belonged to the population, due to the maintenance and use restrictions, until we administered the questionnaire after the vehicle had been randomly selected.

Good read.