Glossary of IAB Metrics

Definitions of the Metrics 

Below are the definitions of the IAB Standard metrics for a given property and publisher:

Auto-refresh Events

The fraction of all events that appear to be triggered by an auto-refresh mechanism. We base our estimate on a frequency analysis of the publisher’s traffic, in which the regularity of auto-refreshed pages stands out from the background of human-requested pages.

Auto-refresh Interval

Distinct Page Views

The number of full, human-requested web pages for which this publisher supplied some or all of the content.  This is calculated from the raw HTML event count. We observed fewer correction factors for non-human traffic, multiple impressions, and auto-refresh.Events received 

We received the number of pixel requests based on a complete count of rows in our server logs.

Multi-events

The fraction of all events that appear to be duplicates–that is, followed within one second by another event from the same user visiting the same publisher. Common reasons include fast redirects (sending the user to a second page as soon as the first has loaded), multiple tagged iframes, or multiple media types being tracked. A Quantified ad network serving ads into multiple iframes on a single page will typically generate multiple pixel requests within a second, and these would be counted as multiple events. Similarly, a publisher using separate tags for tracking pages and the ad placements on those pages will see a significant multi-event count.

Robot Events

The fraction of all events we estimate to be generated by non-human activity. In addition to the IAB’s bot and spider list, we use our own proprietary techniques to identify non-human activity.