Frequently Asked Questions
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.”
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.
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.
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.
Unique visitors represent the number of de-duplicated (counted only once) visitors to the website over the course of a specified time period. Unique visitors are calculated based on the selected reporting period. Any visitor during that reporting period will be counted only once.
Omniture SiteCatalyst is the primary source for the Web Metrics data. The data on Customer Satisfaction is derived from online surveys conducted on CDC.gov, a service provided by Foresee Results.
The majority of the data and information here is not updated in real time and is currently updated on a quarterly basis.
- Page last reviewed: July 31, 2009
- Page last updated: July 31, 2009
- Content source:
- Centers for Disease Control and Prevention
- Page maintained by: Office of the Associate Director for Communication, Division of News and Electronic Media