ABSTRACT
Our society experiences an ever increasing demand for statistical information, but surveys are not the only way to collect such information. A survey is normally conducted to make inferences about a well-defined population. Such a population may consist of individuals, households, firms, schools, farms, or other economic or social institutions. Typically, a survey only collects data about a sample of objects from the population. It is implemented by asking questions about the current or past situation of the objects, historic events, habits, knowledge, or behavior. Data obtained in this way can be used to compute estimates of specific population parameters (totals, means, percentages, correlations, etc.).
