Publications on Research Methodology

This section features selected Pew Research Center reports (since 2005) on methodological issues. Individual project websites contain more reports related to this topic. In particular, please visit the Pew Research Center for the People & the Press, which regularly examines survey research methodology.

Ask the Expert
22 Sep 11Senior research staff answer questions from readers relating to all the areas covered by our seven projects, ranging from polling techniques and findings, to media, technology, religious, demographic and global attitudes trends.
Pew Research Center

How Accurate Are Counts of Same-Sex Couples?
25 Aug 11Two decades after the Census Bureau began offering people the option to describe themselves as a same-sex “unmarried partner,” producing accurate numbers on same-sex couples remains a challenge.
Social & Demographic Trends

Ask the Expert (cont'd)
11 May 11Senior research staff answers questions from readers relating to all the areas covered by our seven projects ranging from polling techniques and findings, to media, technology, religious, demographic and global attitudes trends.
Pew Research Center

The Growing Gap between Landline and Dual Frame Election Polls
Republican Vote Share Bigger in Landline-Only Surveys
22 Nov 10A new analysis of Pew Research Center pre-election surveys conducted this year finds that support for Republican candidates was significantly higher in samples based only on landlines than in dual frame samples that combined landline and cell phone interviews. The difference in the margin among likely voters this year is about twice as large as in 2008.
Pew Research Center for the People & the Press

Cell Phones and Election Polls: An Update
13 Oct 10Data from Pew Research Center polling this year suggest that the landline-only bias is as large, and potentially even larger, than it was in 2008.
Pew Research Center for the People & the Press

Ask the Expert (continued)
19 Jul 10Senior research staff answers questions from readers relating to all the areas covered by our seven projects ranging from polling techniques and findings, to media, technology, religious, demographic and global attitudes trends.
Pew Research Center

Rewriting the 'Race' Question
13 Jul 10A former Census Director also has concerns about the way the government asks about race and ethnicity.
Social & Demographic Trends

Should the American Community Survey Be Voluntary?
6 Jul 10Tests show that if Americans were not required by law to respond to census surveys response rates would drop significantly and the cost of obtaining reliable data would rise considerably.
Social & Demographic Trends

Assessing the Cell Phone Challenge
20 May 10With fully a quarter of the U.S. adult population now relying solely on cell phone service, pollsters and other survey researchers face a difficult decision as to whether to include cell phones in their samples. A joint study by the Pew Research Center for the People & the Press and the Pew Internet & American Life Project takes an up-to-date look at the potential biases in findings based on landline-only surveys.
Pew Research Center for the People & the Press

Conducting the 2010 Census
26 Jan 10Director of the U.S. Bureau of the Census Robert Groves discusses the operational flow of the 2010 Census, design features intended to increase participation, the bureau's communications campaign, real-time monitoring/management, and evaluation of the quality of the census.
Social & Demographic Trends

Accurately Locating Where Wireless Respondents Live Requires More Than A Phone Number
9 Jul 09The mobile nature of wireless phones creates a significant problem for geographic sampling.This problem is exacerbated by the fact that the wireless-only are more geographically mobile than those with landline phones.
Pew Research Center for the People & the Press

Perils of Polling in Election '08
25 Jun 09Despite such challenges as a growing wireless-only population, possible racially-related response bias and greater-than-usual difficulties in forecasting turnout, polllsters' methods were evidently adequate to the task.
Pew Research Center for the People & the Press

Pollwatch: Comparing the Polls on Spending and the Deficit
24 Jun 09How the question is phrased has a clear impact on whether the public rates deficit reduction or stimulus spending more important.
Pew Research Center for the People & the Press

Why Surveys of Muslim Americans Differ
6 Mar 09Because Muslim Americans make up a very small percentage of the U.S. public, it is difficult to provide a reliable picture of their views and differences in survey design can crucially affect findings.
Pew Research Center

New Tricks for Old -- and New -- Dogs
Challenges and Opportunities Facing Communications Research
3 Mar 09Pollsters and other communications researchers are finding their job ever more challenging but also more interesting, and, with the help of new techniques and data sources, even more amenable.
Pew Research Center

Calling Cell Phones In '08 Pre-Election Polls
18 Dec 08The latest study of Pew Research Center election surveys analyzes the effects of conducting both landline and cell phone interviews. While the addition of cell phones had at most a modest effect on estimates of candidate support in individual surveys, when looked at in the aggregate clear patterns emerge.
Pew Research Center for the People & the Press

Poll Power
17 Oct 08Though by no means a perfect instrument, polls make it possible for more opinions, held by a broader and more representative range of citizens, to be known to the government and thus, potentially, heeded.
Pew Research Center for the People & the Press

Cell Phones and the 2008 Vote: An Update
23 Sep 08As in two preceding tests, a new survey shows that including cell phone interviews results in slightly more support for Obama and slightly less for McCain.
Pew Research Center for the People & the Press

Cell Phones and the 2008 Vote: An Update
17 Jul 08The latest Pew Research Center national survey, including a sample of 503 adults on a cell phone, finds that the overall estimate of voter presidential preference is modestly affected by whether or not the cell phone respondents are included.
Pew Research Center for the People & the Press

Research Roundup: Latest Findings on Cell Phones and Polling
22 May 08The Pew Research Center has been studying the challenge to survey research posed by the growing number of wireless-only households. Here's a summary of its latest findings.
Pew Research Center for the People & the Press

How Different Are People Who Don’t Respond to Pollsters?
21 Apr 08Survey research firms face increasingly high non-completion rates. Analysis based on extra efforts to reach non-responders finds few differences between the responses of the easy- and hard-to-reach.
Pew Internet & American Life Project

The Impact of "Cell-Onlys" on Public Opinion Polls
Ways of Coping with a Growing Population Segment
31 Jan 08A new Pew study finds that on key political measures such as presidential approval, Iraq policy, presidential primary voter preference and party affiliation, respondents reached on cell phones hold attitudes very similar to those reached on landline telephones.
Pew Research Center for the People & the Press

Primary Problems: How Exit Pollsters Plan to Cope with a Super-Crowded Election Season
14 Dec 07From holiday distractions to winter weather, the people who will be measuring voters' preferences in primaries and caucuses around the nation will be dealing with unprecedented problems. Here's how they plan to do it.
Pew Research Center for the People & the Press

"Frequently Asked Questions" about Pew's Muslim American Survey
The Facts behind the Design, Conduct and Analysis of a High-Profile Study
2 Jul 07A recent report, "Muslim Americans: Middle Class and Mostly Mainstream," attracted a great deal of attention but also raised a number of questions about the research. Here are answers to some of the most frequently asked questions.
Pew Research Center for the People & the Press

How Serious Is Polling's Cell-Only Problem?
The Landline-less Are Different and Their Numbers Are Growing Fast
20 Jun 07The landline-less are different from regular telephone users in many of their opinions and their numbers are growing fast. Can survey researchers meet this challenge?
Pew Research Center for the People & the Press

What's Missing from National RDD Surveys? The Impact of the Growing Cell-Only Population
20 Jun 07The number of cell-phone-only households has continued to grow -- 12.8% of all households by the end of 2006, according to the National Health Interview Survey. While the noncoverage problem is currently not damaging estimates for the entire population, a study finds evidence that it does create biased estimates on certain variables for young adults, 25% of whom are cell-only.
Pew Research Center for the People & the Press

Can You Trust What Polls Say about Obama's Electoral Prospects?
Two Important Trends Suggest Americans May Now Be Ready to Elect an African American President
7 Feb 07The strong showing of Democrat Barack Obama in early trial heat polls for the 2008 presidential election raises anew the question of whether the American public is ready to support an African American candidate for president. Recent polling points to two significant shifts on this question.
Pew Research Center for the People & the Press

Cell-Only Voters Not Very Different
Fewer Registered, More First-time Voters
26 Oct 06Political pollsters continue to cast a wary eye on the growing number of Americans who use only a cell phone and have no landline. The Pew Research Center estimates that this group now constitutes one-in-ten adults. But three Pew surveys of cell-only Americans this year have found that their absence from landline surveys is not creating a measurable bias in the bottom-line findings.
Pew Research Center for the People & the Press

Are National Polls Reliable Predictors of Midterm Elections?
The record shows that so-called "generic ballots" do a good job
26 Oct 06National elections are the high season for pollsters and with Election Day now less than two weeks away, new polls on the fight for Congress are being released nearly every day. Commonly, pollsters use something called the "generic ballot" to assess the state of the congressional race. Just how accurate is the "generic ballot" in predicting election results?
Pew Global Attitudes Project

Lenski on Exit Polls in the Coming Elections
28 Sep 06In an exclusive interview, Joe Lenski of Edison Media Research reflects on conducting his first election day survey following the death of his former partner, exit poll pioneer Warren Mitofsky. He also reveals steps that will be taken to avoid problems associated with the 2004 poll.
Pew Research Center

Mitofsky on Mexico's Standoff
6 Jul 06Dean of exit pollsters sees Calderon hanging on to lead and expresses confidence in Mexican election system.
Pew Research Center

The Cell Phone Challenge to Polling
15 May 06While Americans who rely solely on a cell phone for telephone service differ in their demographics from land-line subscribers, a new study finds that so far the results obtained by surveys that exclude cell-only users are not significantly affected.
Pew Research Center for the People & the Press