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Frequently Asked Questions

What is a "Page View"?

When a page on the site is visited by 1 visitor, this is counted as 1 page view. This is the replacement for the older term, “page hit.”

What is a "Visit"?

A visit occurs when a single visitor comes to and navigates around the web site. A visit may consist of multiple page views or just 1 page view. A visit is also called a “Session.” The visit/session persists until 30 minutes of inactivity or 12 hours of continuous activity. After this, it’s considered a new visit/session and new visitor.

What is an "Instance"?

For example, each time a search is conducted for a particular keyword, the number of instances associated with that keyword increases by one. The instance metric is displayed in the Referrers, Referring Domains, and most Conversion Reports.

What is a "Clickthrough"?

A clickthrough refers to the number of times a user clicked on a link, button, badge, or graphical image that is linked to another page. When a user clicks on the link and arrived on a landing page, this counts as 1 clickthrough.

Does CDC track Unique Visitors to its Web site?

No. CDC does not track unique visitors or repeat visitors in our web metrics collection. Persistent Cookies have been disabled, therefore we are only able to track visits and page views. This is consistent with meeting federal government privacy standards.

What is the source for this data?

Omniture SiteCatalyst is the primary source for the Web Metrics data. The data on Customer Satisfaction is derived from online surveys conducted on, a service provided by Foresee Results.

How often is this data updated?

The majority of the data and information here is not updated in real time and is currently updated on a quarterly basis.

How can I get additional data or additional information on CDC's Web Metrics?

Contact your requests or questions.

  • Page last reviewed: July 31, 2009
  • Page last updated: July 31, 2009
  • Content source: