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

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

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

  5. What exactly are age-adjusted rates?

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

  7. When working in certain WONDER request screens, why is only the United States offered as the location choice, and lists of specific states or counties are not available?

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 after it's been up a while?

  3. Why does my browser "freeze" when I try to link to certain data queries?

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

  5. 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 plain text (ASCII), web pages (HTML), and spreadsheet files (Comma or Tab Separated Values). All of these facilities are menu-driven, and require no special computer expertise.

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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!


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 or a lengthier mainframe job class. Highly complex queries may require an overnight job class. WONDER data resides on several different computers. This means that some data requests are answered by assembling data from several different systems, which can take longer to process when network traffic is high.

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

Incidence counts and corresponding rates are not revealed when the count falls below a ratio of the representative demographic population. Counts and rates below the determined "cut-off" value are displayed as "missing" in order to prevent revealing cause of death for specific individuals. The cut-off value varies from dataset to dataset, and is decided for each dataset by the data provider. An incidence rate is flagged as "unreliable" when it lies between predetermined values. The corresponding incident counts are too small a sample of the population to provide a valid representative rate. For details on a specific dataset's cut-off values, refer to the documentation for that dataset, or select Help on the dataset's query page.

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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 commas or by tabs. If your software has trouble importing a delimited file, you may wish to remove all titles and descriptive text included in the file above and below the numeric values.

WONDER data requests show the results as web pages (HTML) by default. However, other result formats are also available. Some of the data query applications always produce various output formats. Scroll to the bottom of your WONDER data results screen to see a brief list of links to the data results in other formats. Some of the query applications, such as Compressed Mortality or Census data queries, provide an option on bottom of the request screen where you can select your preferred output file format.

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When working in certain WONDER data request screens, why is only the United States offered as the location choice, and the lists of specific states and counties are not available?

Certain queries provide state and county selection criteria via a Java applet. The applet may not function on your computer for two reasons: (1) Some older browsers do not fully support the Java functionality; (2) Your machine may be behind a secure firewall, which does not allow our server to send the list of states and counties to your browser.

If your request screen does not display state and county criteria, you can still make queries for specific locations by using the requests screens that do not contain Java applets. Try the link for the "non-Java applet" request screen, appearing in the text above the request form.

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. If your machine is behind a secure firewall, we are glad to work with your firewall administrator to resolve the problem.

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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. 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 after it's been up a while?

When this happens, 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.

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Why does my browser "freeze" when I try to link to certain data queries?

Some browsers occasionally experience problems with the Java applets on some request forms. Each of these forms has a link to a non-Java page you can try. 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 browser's "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.

Netscape
Microsoft Internet Explorer

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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.





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This page last reviewed: Wednesday, July 02, 2003

Department of Health and Human Services
Centers for Disease Control and Prevention
Epidemiology Program Office
Division of Public Health Surveillance and Informatics