Harnessing the Wisdom of the Crowd: Public Opinion Poll Data and Research
Here's a scenario with which you might be familiar. You're working on a paper, and you know that the trend of what Americans think about some aspect of your topic is likely to be helpful in making your point. It could be anything from views on the legalization of marijuana, to the importance of the separation of church and state, to the legalization of abortion, to which candidate various groups will support for national office. There seems to be no limit when it comes to opinion polling. How do you get the data you need for your paper? What are the options?
Generally, people using public opinion surveys look for one of three things:
- An individual question that appears in one survey or that appears in several surveys over time (enabling a trend or time-series study). The sought-for elements are the question text (with potential or actual responses) and the frequencies for each response. This aggregate data is also called "marginals" or "toplines." This is the "Yes 40%, No 30%, Don't know 15%, Braindead 5%, Other 10%" information.
- All the questions appearing in one survey. The safest way to retrieve a questionnaire's questions is to start from a known question in, say, iPOLL*, and search on that question's survey organization plus beginning and ending dates. iPOLL*, the Odum Institute* question database, and the Gallup Brain* offer a shortcut that might omit some of those modular questions recycled among concurrent surveys -- for each question retrieved, the database presents a hyperlink that assembles the questions.
- The raw data, or individual respondents' responses to each question, also known as microdata [where marginals are aggregate data]. Seldom if ever would you want microdata, even if you were to say, "I want the data for these questions." In most cases, what you really want are marginals, or frequency of response. Generally, you will need microdata only when you ask as a follow-up question: "I need to know how many Hawaiians hated Ronald Reagan" or "Do poor, uneducated city dwellers approve of school vouchers?" The trigger in these cases is the detail, the subgroups. Other potential microdata uses would involve relations among more than one question: "How many people who like mustard on their pretzels would pay $500 for an Eagles ticket?" Generally, unless you have viewed the survey's questions or codebook, it's likely not worth your time, or the time of the person who's going to help you with using SPSS or SAS, to re-process the raw data.
*It's safe to assume that more than 90 percent of you are interested in either 1. or 2. above. iPOLL, the Odum Institute and the Gallup Brain are the three places most people go for question-level info:
iPOLL (Roper Center), Penn Library Web
Authoritative, includes archived Gallup, Roper, and other pollster questions back to the 1930s. The Roper Center archives ABC News and New York Times media polls as well as Kaiser Family Foundation polls, Los Angeles Times polls, National Opinion Research Center polls, and Wall Street Journal polls; the jewels in the Roper collection are the Roper polls (including the famous "Bowling Alone" surveys), their Japanese and Latin American polls, and the Gallup Organization polls. The LexisNexis version of iPOLL, RPOLL, has identical content, but searching and question formatting are not so good. iPOLL draws from survey organization and survey sponsor press releases, survey reports, data documentation, and lots of other sources. I recommend it most highly.
Odum Institute Public Opinion Poll Question Database, Penn Library Web
A fine small-scale competitor to iPOLL, covering the Harris Polls and the Network of State Polls (e.g., the Pennsylvania Poll, the California Poll). In the "Search" dropdown, choose "Question Text."
Gallup Brain, searchable via Sharon Black, Annenberg School Library
Gallup charges a pretty penny for access to their full archive question database. You will not get access by going through http://www.gallup.com either. As all the old Gallup polls and the main series of recent Gallup surveys appear in iPOLL, you can often get what you need without accessing the Gallup Brain.
There are other places to go for polling data. If you want to explore on your own, feel free to browse the University Library's Research Guide on Public Opinion Polls. However, there are numerous specialized and local polling entities which do not appear in the guide. I would be happy to do my best to help you find and begin to use any of this data