---
title: "About this 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 1,508 adults, 18 years of age or older, from February 20-24, 2008. The following table shows the error attributable to sampling that would be expected at the 95% level of confidence […]"
date: "2008-02-28"
authors:
  - name: "Stacy Rosenberg"
url: "https://www.pewresearch.org/politics/2008/02/28/about-this-survey-2/"
---

# About this 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 1,508 adults, 18 years of age or older, from February 20-24, 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/398-40.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.