Readership Terminology


Average issue readership (AIR)

An estimate of the number of people who read an average issue of a publication. The estimate reflects the number of people who last read any copy of a publication within its publication interval e.g. within the last seven days for a weekly publication.


A count of the number of copies of publication which have been sold/distributed.

Confidence limits/intervals

A statistical calculation of the range of values within which the “true” estimate is likely to lie.

Cumulative readership

The net reach achieved by a publication over a given period of time. A mathematical model is used to calculate what proportion of the target group has the opportunity to see at least one advertisement over this period.


The estimated number of people who read two or more given publications.


Measures of reader engagement indicate the readers’ relationship with a publication, and/or how that publication is read, for example Time Spent Reading. Also known as Quality of Reading.

Extended Media List (EML)

A technique developed to measure a long media list while reducing participant fatigue and the potential for title confusion. It involves presenting the publications initially in groups of six, so that the participant can quickly discard those publications they have not read and focus on answering questions about those that they have read.

Frequency of readership

An estimate of the frequency of exposure to the publication. NRS has three categories to define frequency of readership: Almost Always, Quite Often and Only Occasionally.

Gross readership

A summary of the total number of readership claims for a given group of publications. As some participants will read more than one title, gross readership may exceed 100%.

Net readership

The proportion of the target group who have seen at least one of a given group of publications.


The proportion of the target group who read a particular publication. Also known as Coverage or Reach.

Primary readers

Readers who have obtained their own copy of a publication, be it paid-for or free.


A measure of how likely it is that something will happen or that a statement is true. Probabilities are given a value between 0 (0% chance / will not happen) and 1 (100% chance / will happen).


The way readership breaks down across a single variable such as age, sex or social grade, e.g. what proportion of readers are aged 15-44 versus 45+. Profile data should add to 100%.

Publication period

The time interval between issues of a publication.

Quality of reading

See Engagement

Readers-per-copy (RPC)

An estimate of the number of people who read an average copy of a publication. It is calculated by dividing readership by circulation.

Readership accumulation

A measure of how much time it takes a publication to accumulate its full audience.

Recent reading

The technique which establishes readership (including Average Issue Readership) by asking participants when they last read or looked at any issue of a particular publication.

Regular readership

An estimate of the number of people who read a publication on a regular basis.

Secondary readers

Readers who read a publication which was originally obtained by someone outside their own household. This includes copies seen in public places, at work and so on.