A new survey released by the Center for Immigration Studies and conducted by Zogby International has received considerable attention since its release on December 29, 2009. Public Religion Research reviewed the sampling methodology and the questionnaire design because many of the results were inconsistent with similar questions from the American National Election Study (ANES). Dr. Robert P. Jones, president of Public Religion Research, concludes in the memo, “The CIS/Zogby poll has serious methodological shortcomings, and results should be viewed with considerable caution.”
More from the memo:
Most significantly, the Zogby poll is not based on a scientific random sample of Americans but rather on an opt-in online panel survey. Even though Zogby attempts to balance the panel to make it representative of the U.S. population, the fact remains that this self-selected pool of respondents (i.e., the people who agree to and have the means to participate in online panels) differ significantly from the general population.Why does this matter? Without a random sample such as a random digit dial telephone poll, there is no way to say that the results of this poll accurately reflect opinions in the U.S. general population.
To read the rest of the memo, click here.