Authors: Kuper & Kuper
Summary: The entry defines opinion polls, sketches the history of polling, explains various techniques and technologies, and notes the common uses of polls. Opinion polling is a form of sample survey, meant to measure social and political attitudes.
The first professional polling organization independent of the media was established in 1935, when George Gallup established the American Institute of Public Opinion. Gallup's methods rested on the foundation of random sampling theory. By selecting and interviewing a small sample of voters, the result of a poll will on average faithfully reflect the distribution of opinion within the electorate as a whole.
In Great Britain most opinion polls are undertaken using "quota sampling": interviewers contact a certain number of people with a given combination of characteristics such as age, gender and social class. These quotas are set to ensure that the total numbers of persons interviewed in each quota category reflects their distribution in the population as a whole.
The methodology of opinion polls is also influenced by changes in technology. At first polls were conducted by interviewing people face-to-face in their own homes or in the street. But the spread of telephone ownership to near saturation point in some countries has resulted in an increasing use of telephone interviews.
Opinion polls are frequently used to discover voting intentions. They are also used to provide answers to a range of topical questions; thus they serve to monitor public opinion on such matters as the popularity of governments and party leaders, the salience of particular social or political problems, and so on, and popular preference for different policies.