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FAQ -- Frequently Asked Questions

This page contains answers to common questions handled by our support staff, along with some tips and tricks that we have found useful.
About WONDER...
  1. What is CDC WONDER?

  2. How do I get a quick start with using the features and screens?

  3. How do I find a certain dataset that I heard was available on CDC WONDER?

  4. Why are some data requests returned right away, while other requests take longer?

  5. How are small data values protected to avoid revealing the identities of individual people?

  6. What exactly are age-adjusted rates?

  7. How do I download WONDER numerical data into statistical software, spreadsheets, or graphical packages such as Epi Info, on my PC?

  8. How do I find the citation for data from WONDER?

  9. How do I get permission to use, share, copy or publish information from WONDER?

  10. How do I consent to the data use agreement for data in WONDER?

  11. How are implicitly related data concepts handled in WONDER?

About the Web...
  1. How do I get web pages and documents into a word processor on my PC?
  2. What do I do when my browser fails to respond to commands?
  3. How do I resolve cache setting errors reported by my browser?
  4. Why do I keep getting an error message when trying to connect to the Internet?

What is CDC WONDER?

CDC WONDER: Information and Communication

Wide-ranging OnLine Data for Epidemiologic Research (WONDER) -- is an easy-to-use internet system that makes the information resources of the Centers for Disease Control and Prevention (CDC) available to public health professionals and the public at large. It provides access to a wide array of public health information.

CDC WONDER furthers CDC's mission of health promotion and disease prevention by speeding and simplifying access to public health information for state and local health departments, the Public Health Service, and the academic public health community. CDC WONDER is valuable in public health research, decision making, priority setting, program evaluation, and resource allocation.

CDC WONDER, developed by the Centers for Disease Control and Prevention (CDC), is an integrated information and communication system for public health. Its purposes are:

  1. To promote information-driven decision making by placing timely, useful facts in the hands of public health practitioners and researchers, and
  2. To provide the general public with access to specific and detailed information from CDC.

With CDC WONDER you can:

The data is ready for use in desktop applications such as word processors, spreadsheet programs, or statistical and geographic analysis packages. File formats available include web pages (HTML), chart and map images (bitmaps] and spreadsheet files (ASCII with Tab Separated Values). All of these facilities are menu-driven, and require no special computer expertise.

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How do I get a quick start with using the features and screens?

See the Quick Start Guide for help with using the functions.

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How can I find a certain dataset that I heard was available on CDC WONDER?

CDC WONDER's "home" page provides three ways to find the information you are seeking:

We are always glad to add more data to WONDER. Please contact us with your suggestions!

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Why are some data requests returned right away, while other requests take longer?

Some data requests result in very large data results sets, and your computer may take more time to download and view the data. The number of variables in a request also affects the response time. For example, a database query with several specific disease code ranges and sorted by disease or sorted by year may require more processing time. You can increase the amount of time for the query to run in the last section on any WONDER data request screen. The maximum value is 10 minutes. If the results to your query are not returned within 10 minutes, then please contact us with your specific query criteria for assistance.

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How are small data values protected to avoid revealing the identities of individual people?

In order to protect personal privacy, and to prevent revealing information that may identify specific individuals, small data values are not available in some circumstances. Incidence counts and corresponding rates and other measures are not revealed when the count falls below a ratio of the representative demographic population. WONDER protects small values in the following ways:

  1. The label "Suppressed" is displayed when counts fall below the determined "cut-off" value and the conditions for suppression are met.
  2. Rows showing Totals and sub-totals, are not available when only one row in the results table is suppressed for any summarized section of the table. If an aggregate value represents more than one suppressed row, then sub-totals and totals are available when allowed. If the sub-totals or total values fall within the privacy policy, then these values are also suppressed as applicable.
  3. The Percentage of Total column is not shown when any single row in the results table is suppressed. Note that not all of the online databases report the Percentage of Total measure.
  4. Rows that contain suppressed measures are not sorted by the actual suppressed data value. When the results table is ordered by a column that contains suppressed values, the suppressed values are displayed as though the value was less than zero, instead of showing the suppressed values in the actual sequential numeric order in the table. For example, when data for a specific county are suppressed, and you choose to order the data by rate, then the row representing that county is displayed in the rate value sequence as though the suppressed value was less than zero. The actual suppressed values in the hidden rows are included in the aggregate total values, when totals and sub-totals are displayed.

The "privacy policy" defines the suppression threshold and the specific rules that set the circumstances for when suppression is applied. The privacy policies vary from dataset to dataset. For example, some datasets only suppress county level data when the total population falls below a threshold value, other datasets only suppress data for certain small demographic groups. The policy is determined for each dataset by the data provider in compliance with federal and local privacy regulations. For details on a specific dataset's privacy policy and suppression rules, refer to the documentation for that dataset, or select Help on the dataset's query page. For more information on federal privacy policies, see Data Use Restrictions.

When a larger population, time period or geographic area is selected, fewer values are likely to be suppressed. Some statisticians make use of data smoothing algorithms to reduce the impact of suppressed data. For example, please see "The Impact of Data Suppression on Local Mortality Rates:  The Case of CDC WONDER" by Chetan Tiwari, Kirsten Beyer, and Gerard Rushton, published in American Journal of Public Health, Vol. 104, No. 8: 1386-1388. Available at http://ajph.aphapublications.org/doi/abs/10.2105/AJPH.2014.301900.

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What exactly are age-adjusted rates?

The rates of almost all causes of disease, injury, and death vary by age. Age adjustment is a technique for "removing" the effects of age from crude rates so as to allow meaningful comparisons across populations with different underlying age structures. For example, comparing the crude rate of heart disease in Florida with that of California is misleading, because the relatively older population in Florida leads to a higher crude death rate, even if the age-specific rates of heart disease in Florida and California were the same. For such a comparison, age-adjusted rates are preferable.

Age-adjusted rates are calculated by applying the age-specific rates of various populations to a single standard population. In CDC WONDER, if you choose to age-adjust rates, you must specify your standard population (or accept the default). It is good practice to specify a standard is that generally similar to the populations being compared. For example, if requesting breast cancer mortality rates for white females in Massachusetts for the period 1979-1991, you might specify "1985 Massachusetts white females" as your standard population.

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How do I download WONDER numerical data into statistical software, spreadsheets, or graphical packages such as Epi Info, on my PC?

After requesting numeric data, you may wish to load the data results into a spreadsheet or statistical analysis program. Most analysis software packages can load delimited simple text, when the rows and columns are separated by tabs. If your software has trouble importing a delimited file, you may wish to remove the citation and other reference text included in the file in the first column, below the numeric values.

WONDER data requests show the results as web pages (HTML) by default. Tab-delimited simple text format files are also available for download with the export feature.

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How do I find the citation for data from WONDER?

Each WONDER online database shows the suggested citation in the online "help" file, and also on each screen that displays results for your data request. Look near the end of the page below your table, chart or map to find the suggested citation. Each suggested citation shows the data source, with agency names, data set names and specific release identification when applicable. The date and time of your data query are also shown. If you download data using the export feature, the citation is in the first column, below the numeric values.

When citing written material from a web page, include the web address and the date of access. Use the web address of the first page for citing the online databases, because addresses of the subsequent pages are dynamic after a query occurs.

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How do I get permission to use, share, copy or publish information from WONDER?

CDC WONDER is a public service developed and operated by the Centers for Disease Control and Prevention, an agency of United States federal government. The public web site at http://wonder.cdc.gov is in the public domain, and only provides access to public use data and information. You may access the information freely, and use, copy, distribute or publish this information without additional or explicit permission. Please do provide a citation to credit the authors and/or data providers. When referring to a written article or document, please cite the item as you would any other document on the world wide web.

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How do I consent to the data use agreement for data in WONDER?

Any use or access of the data and information available in WONDER implies your consent to our data use agreement. Review the Data Use Restrictions carefully before using WONDER. All data are covered by the provisions of the Public Health Service Act (42 U.S.C. 242m(d)) .

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How are implicitly related data concepts handled in WONDER?

Some of the data stored in the CDC WONDER online databases have implicit relationships or connections to other data. For example, specific counties are located within certain states and regions. When you limit data to Delaware and group results by County, you see data for the counties within Delaware. In the mortality online databases, causes of death are categorized in several ways, such as International Classification of Disease (ICD) codes, or as drug and alcohol-related causes, or as Injury Intent categories. When data are grouped by Cause of Death specified as ICD Codes, and also limited to the Unintentional Injuries category, then the results show only those ICD codes that fall into the Unintentional Injuries group. The implicit relationship between these two data fields, ICD codes and Injury Intent, is observed when the query is processed. Until May 30, 2014, CDC WONDER only took these relationships into account for ontologically related hierarchical data, with clearly ordinate parent-child relationships, such as region/division/state/county and ICD chapter/sub-chapter/code. Now these implicit relationships are also taken into account when querying data with peer relationships, for the following data items:

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How do I get web pages, pictures and documents into a word processor on my PC?

To get a section from a web page:

Use your mouse to "click and drag" and highlight your desired selection from the page. Then "copy" the selection, move to your word processor with the target file open, place your cursor where the selection should go, and "paste" the selection. The "Copy" and "Paste" commands are usually found in your web browser's "Edit" menu at the top of the window, or found by clicking the right-hand mouse button. To select an image, such as a map or chart, then right click your mouse on the desired image. A menu pops open with options to capture and copy the image. Note that the map legends are separate image files. Your computer may also have "short-hand" key strokes for these commands.

To get the entire web page:

When a desired document is displayed in your browser, click on the "File" menu option at the top of the browser, then select "Save As." This action saves the web page to a file on your computer, and you can choose the file's name and location, and the file format. Later, you can "open" this file with your web browser or other software applications, such as a word processor. If your word processor cannot load web pages (HTML file format) then save the document as a text file.

Refer to the help feature for your computer's operating system, and for your specific desktop applications to learn more.

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What do I do when my browser fails to respond to commands or seems "stuck" loading a page?

Some large and complex data requests can take several minutes to process, and again take additional time and memory to download the results and display in your web browser. Please be patient with complex queries, and allow up to 10 minutes.

If your web browser is unable to load a page, then exit your browser and reopen it. If you cannot exit the web browser, try to end the process, for example by using the "Task Manager" for a "Windows" computer. If the problem still persists, exit all applications and shut down and then restart your system. Another application you are running may be conflicting with your browser.

We would appreciate it if you would inform us of any problems your browser has while using CDC WONDER. You can e-mail us at cwus@cdc.gov. Browser version and release information is displayed in your browser's "About" option under the "Help" menu.

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How do I resolve cache setting errors reported by my browser?

These problems can be resolved in your browser setup. You should contact your Internet Service Provider or search the help function of your browser. Here are some links to common browsers to help you expedite a resolution.

Microsoft Internet Explorer
Mozilla Firefox
Netscape

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Why do I keep getting an error message when trying to connect to the Internet?

These types of messages usually result from trouble connecting to your Internet provider. You should contact your provider's technical support for assistance.

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What if my question isn't addressed here?

CDC WONDER is a product of Centers for Disease Control and Prevention. Questions or problems regarding this web site should be directed to cwus@cdc.gov.




This page last reviewed: Monday, August 18, 2014
This information is provided as technical reference material. Please contact us at cwus@cdc.gov to request a simple text version of this document.