A survey is a method of collecting data from a sample of individuals, usually via questionnaire, and then extrapolating this to estimate the characteristics of a larger population. It is one of the main research methods used in social sciences such as sociology, psychology, epidemiology and political science.
There are different types of surveys, but they all share some common features. First, surveys must have a clearly defined target population from which the sample will be drawn. Second, the sample must be selected in a way that ensures that it is representative of the target population (i.e., random sampling). Third, the questionnaire must be designed to collect reliable data on the variables of interest. Finally, the results of the survey must be analyzed and interpreted carefully.
The advantages of surveys include their flexibility (they can be adapted to study almost any phenomenon), their relatively low cost, and their ability to collect detailed information on a large number of individuals. The disadvantages include potential non-response bias (if certain groups are more likely to respond than others) and self-report bias (if respondents do not answer honestly).