ABSTRACT
In Chapter 5 we learned how to use the laws of probability to assist us in making decisions about observed events. The examples used in Chapter 5 provided all of the information needed to reach those particular conclusions. In sociological research, however, we frequently do not have access to all of the necessary information. For example, we might want to know what the American people think about nuclear disarmament. Depending on how we define "American people," this population could have as many as 250,000,000 people. It would require extraordinary resources to gather so much information, and such tasks are attempted only once every ten years. Given that no one but the Bureau of the Census has the capacity to study the entire population of 250,000,000 American people, does this mean that our original question cannot be answered, cannot even be asked? It does not, for we can, with a very high degree of confidence and with only a small amount of error, obtain the answer to our question by using data from a sample of the larger population. From the sample data, we can make inferences about the population. And the inferences we make will not be at all haphazard.
