How to lie with statistics - Trick #1: Select your sample with bias
(If you go “Lying with statistics is unethical - what is this?” then read the intro)
A very simple trick to fool the crowd is to conduct your survey under “the right circumstances”, e.g., select carefully when or who to ask in order to get the answer you are looking for. For example:
- If you want to show that the political conservatives are getting ahead of the socialists, then just ask people outside the church og financial district instead of the supermarket or subway.
- If you want to demonstrate that many people are frustrated with delays in the airport - then ask them on a day with heavy rain and many delayed airplanes.
- If you want to prove that your garden product gives fantastic results, make sure to make the test in a year of good conditions.
If your want to counter the results of a survey, investigate carefully how the data was collected and how this affects the outcome. Everybody making a survey has a preferred outcome, and if you have identified the preferrences, you can start think of how this most likely have influenced the sampling - conciously or not.