“Four out of five dentists surveyed recommend sugarless gum for their patients who chew gum.” The slogan “became strongly associated with the Trident brand.” When it was first used is not certain. Sources date the survey to the early 1960s or to 1976.
The wording is careful. The dentists were “surveyed,” and the advice is for “patients who chew gum.” The fifth dentist “usually recommended no gum at all.”
From 2005 to 2010 the CBS series Numb3rs ran for six seasons and 118 episodes. A mathematics professor helps his brother, an FBI agent, solve crimes. The opening narration began: “We all use math every day. To predict weather… to tell time… to handle money.” It continued: “Math is more than formulas and equations. It’s logic; it’s rationality. It’s using your mind to solve the biggest mysteries we know.”
Article I, Section 2 of the Constitution says that “Representatives and direct Taxes shall be apportioned among the several States” according to their population. The first census was taken in 1790, directed by Thomas Jefferson. Today the census divides “the 435 memberships, or seats, in the House of Representatives among the 50 states.”
The Census Bureau calls apportionment the census’s “initial use.” Every ten years, the share of political power each state holds in the House is set by a count.
American office English has many phrases that send an argument to the numbers.
crunch the numbers — “to examine and analyze numbers,” especially to find out how much money is available or needed.
number cruncher — “a person concerned with numerical data (such as statistics).”
by the numbers — “in a systematic, routine, or mechanical manner.” It began as a drill command, done to a count.
run the numbers — check whether a plan works before deciding on it.
the numbers don’t lie — said to end an argument.
show me the numbers — the usual answer to a proposal without figures.
The American social scientist Donald T. Campbell stated a rule in 1976: “The more any quantitative social indicator is used for social decision-making, the more apt it will be to distort and corrupt the social processes it is intended to monitor.”
He applied it to schools: “when test scores become the goal of the teaching process, they both lose their value as indicators” of what students know. Critics later cited Campbell’s law against the federal school programs No Child Left Behind and Race to the Top.
In the Vietnam War, the American military treated the enemy body count as a “precise and objective measure of success.” In 1962, Brigadier General Edward Lansdale reportedly told Defense Secretary Robert McNamara to add an “x-factor” to his list of measures: the feelings of rural Vietnamese. McNamara reportedly erased it, because he could not measure it.
The public-opinion researcher Daniel Yankelovich later described the reasoning in four steps. “The first step is to measure whatever can be easily measured.” The last: “The fourth step is to say that what can’t be easily measured really doesn’t exist. This is suicide.” The error is now called the McNamara fallacy.
During the Great Depression, American policy makers “had no reliable measure of economic activity.” The Senate commissioned a study, and the economist Simon Kuznets carried it out. In 1934 he delivered “National Income, 1929–1932” to Congress as Senate Document No. 124.
In the same report Kuznets warned: “The welfare of a nation can scarcely be inferred from a measurement of national income.” He received the Nobel Memorial Prize in Economic Sciences in 1971.
Google compared the interview scores of its employees with their later job performance. In 2013 Laszlo Bock, Google’s head of people operations, told the New York Times: “We found that brainteasers are a complete waste of time. They don’t predict anything. They serve primarily to make the interviewer feel smart.”
Comparing interview scores with later job performance showed “zero relationship,” Bock said, “a complete random mess.”
In 1954 Paul Meehl, a psychologist at the University of Minnesota, published Clinical Versus Statistical Prediction. He compared the judgment of experienced clinicians with predictions made by simple formulas. His analysis favored the formulas and “caused a considerable stir amongst clinicians.” Meehl described the clinicians’ preference as “using our heads instead of the formula.”
Meehl later reported that “half the clinical faculty at one large Freudian oriented midwest university were plunged into a 6-month reactive depression.” Later meta-analyses supported his claim. On average, mechanical prediction was about 10 percent more accurate.
Before the 2012 presidential election, the statistician Nate Silver gave Barack Obama a chance of “more than 70 per cent,” and then “north of 90 per cent.” MSNBC host Joe Scarborough called Silver “a joke.” He said anyone who thought the race was “anything but a tossup right now” was “such an ideologue.”
Silver’s forecast called the result correctly in all 50 states. In 2008 he had called 49 of the 50, missing only Indiana.