Glossary

The Clutter Index (or Advertising Clutter Index) is a metric used in media planning to measure the density of advertising messages within a specific medium or communication channel (such as a magazine, a television broadcaster, or a web page) during a given time interval. In simple terms, it indicates "how crowded" a space is with advertising, by relating the total advertising space to the editorial or content space.

The Audience Rating (or Audience) is a metric that quantifies the number of people or devices exposed to a particular piece of content (such as a television programme, radio broadcast, or an advertising message) within a specific time interval. It is the fundamental measure for determining the success of a programme and the value of the corresponding advertising slots.

The Attention Index (or Attention Score) is a composite metric used in digital advertising and media planning to measure the real effectiveness of an advert in capturing a user's active interest. Unlike viewability (which only measures whether an advert could be seen), the attention index seeks to quantify whether the advert was actually looked at and for how long.