Читать книгу Our Social World - Kathleen Odell Korgen - Страница 93

It would be impossible to interview or send a questionnaire to every school dropout in Brazil to determine why the teenage dropout rate is so high. It is possible to study a portion of that population, however. In Step 5, the research design process includes determining how to make sure the study includes people who are typical, that is, representative, of the total group (or population) you want to learn about. This involves careful selection of a sample, a group systematically chosen to represent a much larger group.

Researchers use many types of samples. A common one, the representative sample, attempts to accurately reflect the group being studied so that the sample results can be generalized or applied to the larger group or population. In the case of studying why so many boys from Hector’s favela drop out of school, a representative sample for a study could be drawn from all 13- to 16-year-olds in his region or city in Brazil.

The most common form of representative sample is the random sample. All people in the population being studied have an equal chance of being selected for the study. By observing or talking with this smaller group selected from the total population under study, the researcher can get an accurate picture of the total population and have confidence that the findings apply to the larger group. Developing an effective sampling technique is often a complex process. In the case of Brazil, people constantly move in and out of the favela. Those who have just arrived may not have the same characteristics as those who have been living there a long time, but it is important to have a sample that represents the whole group being studied. Samples also must be large enough to accurately represent a population and to use statistical programs to analyze the data. If you take a methods course, you will delve further into these details of sampling and data analysis discussed next.