The key measure of readership is known as Average Issue Readership or AIR.

AIR is the number of people who have read or looked at an average issue of a publication.

The definition is based on those who say they have last read a publication within its publication interval, i.e:

Daily newspapers Read yesterday
Sunday newspapers Read in the last 7 days
Weekly magazines Read in the last 7 days
Fortnightly magazines Read in the last 2 weeks
Monthly magazines Read in the last month
Bi-monthly Read in the last 2 months
Quarterly Read in the last 3 months

For daily newspapers AIR is available for Saturday editions, as well as an estimate for the 5-day weekday edition, and an overall 6-day estimate.

To qualify as a reader, the publication must have been read or looked at for at least 2 minutes. In fact, publications are read for much longer than this, as the time spent reading data show.

There is also a great deal of other information about readership available from NRS.




Average Issue Readership (AIR) is an indication of potential audience, rather than a measure of how many people will have seen a particular advertisement within a specific edition.

However, NRS does include a number of measures to assess how each publication is consumed and what implications this might have for the advertising placed within them.

The measures available are:

Frequency of reading
Source of copy
Time spent reading
Readership accumulation over time
Finally, as well as AIR, the full range of options as to when the publication was ‘last read’ are available for analysis. This can be useful when comparing print with other platforms, such as the Internet.




Three measures of reader engagement are available on the NRS:

  • Frequency of reading
  • Source of copy
  • Time spent reading

Frequency of reading describes the reader’s relationship with the publication. It is also used to generate the readership probabilities for schedule analysis models.

Source of copy is an indicator of the reader’s relationship with a publication. Detailed information is available as to who obtained the copy and how it was obtained. NRS also provides an overall classification of primary and secondary readership based on source of copy.

Time spent reading is a measure of reading intensity which can be used to compare publications.




Different publications accumulate readership at different speeds. This obviously has implications for advertising planning.

NRS has conducted a study of how readership builds over time, and the results are available for time-based planning.

The time taken to accumulate readership depends not only on the publication interval, but the content of the publication, and how it is obtained, read and passed on to other readers.

The following chart shows some examples of the differences in how long various publications take to accumulate their audience.

The readership accumulation curves for all titles are available in the subscriber section of this website.

The information is also available through the computer bureaux, to enable subscribers to plan time-based press schedules.




NRS publishes readership estimates for over 230 very different types of publication, including:

  • 26 national daily and Sunday newspapers
  • 8 regional newspapers
  • 158 consumer magazines
  • 39 newspaper supplements

(Source NRS January-December 2012)

The average respondent will have read 15 of these publications in the past year. Great care is needed to ensure that they can identify these titles from the long list of over 300 publications they will be shown initially.

When measuring readership the five key principles are:

  1. Create a level playing field, so that all publications are measured on a like-for-like basis.
  2. Move respondents efficiently through the long list of titles surveyed, so that they can identify the titles that they do read. This is done by means of the Extended Media List (EML) technique which presents titles initially in groups of six, so that the respondent can decide which groups of six include titles that they have read and discard the rest.
  3. Make respondent recognition the key principle when deciding how to prompt titles and allocate them to the EML screens.
  4. Minimise title confusion by prompting titles which may be prone to confusion alongside one another.
  5. Rotate the order in which publications are presented to respondents to avoid bias and offset any fatigue effects. Not only is the overall order rotated, but also the position in which each title is shown in its group of six. For a full description of the rotations used, please see please see Technical Information




Publications are shown in groups of six. Respondents are asked to select which screens show any publications that they have read in the past 12 months.

Typescript prompts are used to make the screens easy for the respondents to scan, and to ensure that no particular publication appears dominant.

There is a check as to whether any screens have been excluded in error.

Respondents are then asked about each publication on the screens they have selected. At this stage they are asked whether they have read the publication in the past 12 months.

For both the screen check and the Read Past Year (RPY) question, NRS uses a prompt showing the mastheads of the titles.

Once we know all the publications which qualify as Read Past Year (RPY), the respondent is asked when they last read each publication and how often they read it.

There are also special prompts which are used to help respondents identify which newspaper supplements they have read.




NRS has developed a Special Reading Question for ASOS magazine and like titles that are print products of established digital brands. This has enabled us to meet the needs of an emerging publishing market that is difficult to accommodate using the standard NRS screen prompts, because there is a greater risk than for other titles on the Survey of confusion amongst respondents between the print title and the website.

The Special Reading Question was added to the Survey in April 2011. The aim of this question was to produce a more reliable estimate of the print title by filtering out respondents who had only visited the website.

The data from this special question was reviewed, and ASOS magazine has surpassed the minimum number of unweighted respondents for it to be eligible for publication by NRS. It was agreed that the estimate for ASOS magazine should be released with effect from data periods ending September 2011. The estimate for ASOS magazine is published separately from other titles, under the Special Reading Question heading, to draw attention to the fact that there are differences in the way in which its estimate is derived.




All estimates based on a sample are subject to what is known as ‘sample variation’. However tightly controlled, the answers from one sample of people will differ somewhat from another sample of people drawn in exactly the same way.

There are various statistical tests which can be used to assess whether changes in NRS data from period to period (or between publications) are actually real changes rather than the result of sample variation.

For any estimate taken from the NRS it is possible to work out a ‘confidence limit’. This is a way of expressing how much variation we might expect. For instance:

  • Magazine X has estimated readership of 1,818,000 adults (3.7% of adults)
  • The 95% confidence limits for this estimate are +/- 125,000
  • This means we can be 95% certain that the true estimate for Magazine X is between 1,693,000 and 1,943,000 (3.4% to 4.0% of adults)

NRS has created two easy-to-use spreadsheets to:

  • Find out the confidence limits for a particular estimate, be it readership or any other estimate on the survey.
  • Find out whether the difference between two estimates is statistically significant
  • All users need to do is to enter the estimates they wish to test into the boxes shown on the spreadsheet, along with the population and sample size on which the estimates are based.

NRS also has available a booklet called ‘Statistical tests for NRS data’ which goes into more detail about the tests, and the formulae on which they are based.




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 respondent fatigue and the potential for title confusion. It involves presenting the publications initially in groups of six, so that the respondent 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 respondents 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 respondents 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.




To view NRS Data as probabilities please click here