Statistics based on well designed research in many fields provide insights for further research and decision-making by leaders in both academic and ecclesial communities.  A religious reference librarian should know the best print and on-line sources for reliable statistics, especially related to religious practice, ethics, and human behavior, but also in economics, education, and medicine.  The statistics in this module deal with opinion polling and sociological studies, using data from a variety of religious and secular sources. Statistics related to the number of adherents in different religious groups can be found in the denominations module.

Basic Understanding of Statistics

Polling Data

The Hartford Institute for Religious Research has links to helpful instructional materials about polling data and statistical interpretation. Since much of the research related to religious studies involves opinion polling, this site is very helpful.

There is basic information about how data is interpreted here:

For further reading:  The StatSoft electronic textbook on statistics is recommended by the Hartford Institute for Religious Research.

Questions to answer:

  • The Barna Update identified a range for sampling error, and I don’t know what that means.  Can you help me understand?

  • What are the characteristics of a good telephone poll?

Sources to Know

1. Association of Religion Data Archive:

In addition to statistics on affiliation, the ARDA allows users to explore the highest quality data on American and international religion using interactive features for generating national profiles, maps, church membership overviews, denominational heritage trees, tables, charts, and other summary reports. Over 350 data files are available for online preview and most can be downloaded for additional research, including studies on religious professionals and religious groups (individuals, congregations, and denominations). Also provides the 2004 General Social Survey, the National Congregations Study (see NORC below). Offers background information, survey questions (codebook), keyword searching of all data files, and applications to create custom surveys and maps using many variables. Excellent tutorials are well worth the time to work through. Tutorials for use found at

2.  Pew Forum on Religion and Public Life 
Pew funds many studies on religion.  This site has good search function, surveys on issues, and a few downloadable datasets. One noted study is the U.S. Religious Landscape Survey, based on Interviews with 35,000 Americans and released in 2008. This survey includes social and political views as well as demographics.  Detailed data tables on opinions and issues can be found at (Report 2, Appendix 2).

Pew also funds research in other areas of social science with implications for religion and and practice of ministry.

3.  Hartford Institute for Religion Research

A large collection of the institute’s original research and links to many other sources of both demographic and opinion based research.  Full research reports and data are available on tipcs of congregations, megachurches; women and religion; religion and family; and orthodoxy. Other topics have articles and links to hundreds of web sites of organizations and resources related to religious research.  (See

Faith Communities Today-Cooperative Congregations Studies Partnership Project is the Institute’s premier project.
The 2000 research project was undertaken in 1999-2000 and was officially released March 2001. This study of over 14,000 congregations was the largest survey of congregations ever conducted in the United States.  Another survey was conducted in 2005, with reports released on Insights into Growth and Insights into Conflict. Results of a 2008 survey were released in April, 2009.

4.  Pulpit and Pew

Pulpit & Pew is an interdenominational project aimed at strengthening the quality of pastoral leadership (clergy and lay) in churches, parishes, and other faith communities across America. (from the site)  See Research Reports, Publications, and Links.

National Clergy Survey conducted in 2001 is being analyzed and presented in research reports, available as .pdf file on this site.

5.  US Congregational Life Survey

As part of the U.S. Congregational Life Survey, about 300,000 worshipers in over 2,000 congregations in the United States completed a survey during worship services in April 2001. Worshipers in Australia, England, and New Zealand completed similar surveys. Together, the international effort included about 2 million worshipers and 17,000 congregations across three continents. (from the web site) The U.S. Congregational Life Survey is the largest and most representative profile of worshipers and their congregations ever developed in the United States.

6.  National Congregations Study
Research by the National Opinion Research Center was conducted in 1998 and 2006.  A representative sample of congregations was identified by question about religious service attendance on the GSS (see NORC below).  The NCS then gathered data from these congregations using a one-hour interview with one key informant--a minister, priest, rabbi, or other staff person or leader--from each nominated congregation. These interviews were mainly conducted by telephone, but if telephone contact was difficult the interviews were conducted in person. Data from both surveys can be accessed at this site.


  1. Compare findings from two surveys about attitudes toward religious services.

  2. Find a research report on the participation of women in Christian churches.

More Opinion Polling

These organizations doing frequent opinion polling related to religion.


To find descriptions of original research, you must open “Barna Updates.”  The methodology is found near the end of each article under the subtitle “About the Research.” Pay close attention to definitions and be aware that commercial services and book sales are part of the organization’s mission.


Conducts frequent telephone polls in the US and globally. A recent study of over a billion Muslims resulted in a book featured at the site.

National Opinion Research Center at the University of Chicago (NORC) 

NORC has a 60 year history of respected and valuable polling used by the government and many academic partners. Their mission is to conduct high quality social science research in the public interest.´ Since 1972. NORC has conducted the (now biannual) General Social Survey.  This survey is conducted face-to-face with non-institutionalized adults in the US. “Except for the U.S. Census, the GSS is the most frequently analyzed source of information in the social sciences.” (from the website)  Detailed information and datasets are available.  NORC has also participated in the International Social Survey Programme which has conducted three major studies of religious affiliation in the last 18 years. 

Roper Center

The Roper Center for Public Opinion Research is one of the world's leading archives of social science data, specializing in data from surveys of public opinion. The data held by the Roper Center range from the 1930s, when survey research was in its infancy, to the present. Most of the data are from the United States, but over 50 nations are represented. (from the website)

Denominational Research Offices

National church offices often provide a variety of stats from demographic to clergy records to giving patterns to opinions surveys which can be helpful to leaders in local churches or researchers in academe.  This compilation from the Hartford Institute is helpful.  as are the direct links below. 

Government Statistics

Fed Stats 

From this site, you will be able to search different topics, agencies, and programs to find federal, state, and local statistics.

Census Bureau

Religious researchers and organizations need access to accurate demographic data to better understand and serve people.  A frequent reference task is preparing a profile of a community served by a particular church or organization.  ARDA has an tutorial on constructing such a profile, the Community Profile Builder, at  Pages 23-24 of the specifically demonstrate how to extract information from census data.

American Factfinder:

American Factfinder is an interactive, searchable database on the Internet that is used to find population, housing, industry and business statistics from the U.S. Census.  It is authored and maintained by the U.S. Census Bureau.  As with most complex interactive software, using it is challenging.

A short tutorial to define and extract information from census data follows:

  1. Go to
  2. Choose American Factfinder from the left column.
  3. Select “get data” from either the Decennial Census or the American Community Survey.
  4. Choose any of the summary files or surveys from the center column.
  5. Click on “detailed tables.”
  6. Select a geographic type from the dropdown menu. These range from national to zip code or school district.
  7. New windows will generate depending on your selection.
  8. Make choices from all generated windows and click “Add.”
  9. You may repeat the process to add other geographic types for comparison.
  10. When finished selecting, click “Next.”
  11. On this screen find the detailed tables by searching subject, keyword, or browsing. through all tables in the summary file or survey.
  12. Select as many tables as you desire by highlighting and clicking “Add.”
  13. Finally, click “Show results.”

Exercise:  Find the number of single parent households in your state and school district.

Hint: Use American Community Survey; select appropriate state and school district; proceed to tables and search keyword “children;”  Select B11005. (Others to consider B11003, B11004, B09002, B09005)

This organization analyzes demographic information for congregations. Some customized reports are complimentary with a simple registration.  A six page FirstView shows demographic information from a selected geographic area. Other services require a fee, but denominational bodies may already have accounts. Contact any association on this list for more information. 

Other agencies with helpful statistics:

International Statistics