Collection of Data

Abstract

To answer these questions and an enormous number of other ones, information must be gathered. In these instances, we need to know many things, from sexual habits to recycling practices. At first glance it seems easy to get this information. One needs only to go out and ask people or do an experiment to see how things work. But then the quandaries begin: Who should do the asking—you, me, unemployed college students, retired executives? And who should be asked? Can we afford to ask everyone concerned with the problem? For the first question, that would be the entire population of Los Angeles! Well, if not everyone, how about people who walk by a certain store at the mall on Saturday afternoon? Or those buying beer at the baseball stadium? Or do you think a presumably fairer way should be found?

How many people in Los Angeles were infected with AIDS by a sexual partner last year? How much garbage was recycled in New York City last year? What caused scurvy to attack seventeenth-century sailors on long voyages? Does class size affect school performance? Is the President doing a good job?