A questionnaire is never perfect: some are simply better than others. A quote of American statistician and quality control pioneer William Edwards Deming (1900-1993). The quote appears on page 31 of Deming's book "Some Theory of Sampling" (John Wiley & Sons, 1950) . The quote also appears in "Statistically Speaking: A dictionary of quotations" compiled by Carl Gaither and Alma Cavazos-Gaither.
- Prof Dev