CASE STUDY Every autumn, U.S. News & World Report publishes a story ranking accredited four-year colleges and universities throughout the United States. These rankings by U.S. News & World Report are very influential in determining public opinion about the quality of the nation’s colleges and universities. However, critics of the rankings question the quality of the data used to rank schools. In the January 2012 article “Gaming the College Rankings,” the New York Times described several instances of “fudging the numbers” by colleges in order to climb in the rankings.

Business data, advertising claims, debate on public issues—we are assailed daily by numbers intended to prove a point, buttress an argument, or assure us that all is well. Sometimes, as the critics of the U.S. News & World Report rankings maintain, we are fed fake data. Sometimes, people who use data to argue a cause care more for the cause than for the accuracy of the data. Others simply lack the skills needed to employ numbers carefully. We know that we should always ask

We also know quite a bit about what good answers to these questions sound like. That’s wonderful, but it isn’t enough. We also need “number sense,” the habit of asking if numbers make sense. Developing number sense is the purpose of this chapter. To help develop number sense, we will look at how bad data, or good data used wrongly, can mislead the unwary.