Technology

The traffic is monitored by NAVRCHOLU.cz using special HTML code (a script), which is inserted into all pages of the monitored site. If the page is then requested from the server by a visitor, the script starts an action on the monitoring server and the server receives the required data about the visit and the visitor.

The script appears as an image to the outside world (either visible or invisible), which means that only requests by browsers which display images are counted (this is, of course, the case for the vast majority of them), while accesses by various robots which index WWW pages for search engines are excluded.

Methodology

The methodology is based on the recommendations of IF ABC, which is a voluntary association of professional organizations established to certify press circulations. With the advent of the Internet, the IF ABC Web Standards Committee adopted standards for auditing web server circulations. The current version of the standards is available online at www.ifabc.org.

Of the terms defined by IF ABC, these in particular are used by NAVRCHOLU.cz:

• page impression
  A file, or a combination of files, sent to a user as a result of that user's request being received by the server.
• unique user
  The total number of unique combinations of an IP address plus a further identifier (cookie).
• visit
  A series of one or more page impressions, served to a valid user, which ends when there is a gap of 30 minutes or more between successive page impressions for that user.

The terms are described in more detail in the NAVRCHOLU.cz Help.