---
title: "About the Survey"
description: "Results for this survey are based on telephone interviews conducted under the direction of Princeton Survey Research Associates International among a nationwide sample of 1,505 adults, 18 years of age or older, from May 21-25, 2008. The following table shows the error attributable to sampling that would be expected at the 95% level of confidence […]"
date: "2008-06-03"
authors:
  - name: "Seth Rubenstein"
url: "https://www.pewresearch.org/politics/2008/06/03/about-the-survey-404/"
---

# About the Survey

Results for this survey are based on telephone interviews conducted under the direction of Princeton Survey Research Associates International among a nationwide sample of 1,505 adults, 18 years of age or older, from May 21-25, 2008. The following table shows the error attributable to sampling that would be expected at the 95% level of confidence for different groups in the survey:

![](https://assets.pewresearch.org/wp-content/uploads/sites/5/legacy/426-5.gif)

In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.