Today's Question: How is public opinion scientifically measured?
Vocabulary:
exit poll
Gallup Poll
poll
random sampling
referendum
sampling error
straw poll
Introduction:
Three Ways to Measure Public Opinion:
-elections
-public referendum
-public opinion polls
The scientific measuring public opinion is a fairly recent phenomenon. While straw polling dates back to the early 1820s, its practice was hardly scientific and remained fairly localized in scope. The first real attempt at national polling came from the Literary Digest, who in 1916 began to send out postcards to its readers to their opinions. But this venture was hardly scientific and its results were quite skewed, leading to misleading conclusions. In 1936, Literary Digest predicted, based on its returned postcards, President Franklin Roosevelt would lose in a landslide to his Republic opponent, Alf Landon. The complete opposite happened. This polling fiasco reinforced the need for a more scientific approach to polling if public opinion was to be gauged accurately.
George Gallup was engaged also during the Great Depression, and he was devising better, more accurate methods of polling. They were, of course, also flawed and helped lead to the 1948 election disaster that predicted, using quota sampling, Thomas Dewey had defeated President Harry Truman. Again, the polls were wrong. But Gallup would soon learn from his mistakes and help develop more scientifically accurate method of polling through random sampling. Today, using many of Gallup's refined methods, over 1,000 polling organizations attempt to measure everything from television shows to musical tastes to preferences in soft drinks. Some 200 organizations are dedicated to understanding America's political preferences.
The best polling in the data-driven era is attained through the aggregation of polls into a meta-data format. For example, combining the results of several polls from different organizations and correcting for previous outcomes provides some of the most accurate predictions. One of the key pioneers in this field is Nate Silver who started as a baseball statistician and is now one of the most energizing talents in the world of polling. Take a few minutes to read his predictions about the next Senate.
PART ONE: Understanding Polls
Activities:
Click on "Understanding Public Opinion Polls". In your groups, preview the following questions together. Individually read the article and then answer the questions at the bottom as a group. Be prepared to discuss in class and to answer today's question.
1. Historically, why and how was the Literary Digest poll of 1936 and the Gallup Poll of 1948 flawed? What lessons about polling were learned from these two polling mistakes?
2. In a poll, why must there be a clear and accurate link between sample and population?
3. What problems can be created by public opinion polls?
4. What are exit polls?
5. Why do most polls today rely primarily upon phone banks?
6. Could instantaneous polls via the Internet help or hinder American politics? Why?
7. What is meant by a poll's "sampling error"?
*Remember that to be valid and reliable, polls must be scientific. This means that the sample taken must be both randomized and representative of the overall population being focused on. The sample should be large (1,000 to 2,000 people) and thus the margin of error small (typically between 2 and 5%).
PART TWO: How Politicians Use Polls
Read this brief excerpt from Genovese and Streb, Polls and Politics: The Dilemmas of Democracy (pages 25 -26):