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 newsbrands |  |
Read yesterday |
| Sunday newsbrands | |
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 newsbrands AIR is available for Saturday editions, as well as an estimate for the 5-day weekday edition, and an overall 6-day estimate. The 6-day estimate is a modelled figure and should be used rather than manually combining estimates for Saturday editions and 5-day weekday editions.
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.
