NRS estimates for any title are normally based on a minimum period of 6 months, if the title has accumulated a sufficient number of unweighted Average Issue Readership (AIR) participants.
However, in the case of titles newly added to the survey, the intention is to publish a first estimate after as short a period of measurement as possible.
This is achieved under the following rules:
•No estimates for any title new to the survey will be released on less than one month’s fieldwork. Where a title is newly launched, no estimates for that title will be released until at least four consecutive issues have been published.
•Subject to 1 above, estimates for a title newly added to the survey will first be released when the title achieves a minimum of 175 unweighted AIR participants. If such an estimate is released on less than a 6-month sample, subsequent estimates will be based on the cumulative monthly sample achieved by the title until a 6-month base has been accumulated.
•Thereafter estimates for such a title will be released each quarter on a rolling 6-month base, and rolling 12-month estimates will also be released as soon as a 12-month base has been accumulated.
•If this minimum of 175 unweighted AIR participants is not reached after 6 months, but is reached after between 7 and 12 months of measurement, the first estimate released will relate to the period in which the sample threshold is reached (e.g. 9 months January-September). Once such an estimate is released, further estimates for the title will be based on the cumulative monthly sample until a 12-month base is achieved. Subsequent estimates will then be based on a rolling 12-month base.
•If this minimum of 175 unweighted AIR participants is not reached after 12 months, estimates can still be released if the title achieves 225 unweighted AIR participants after 24 months. However because of the data processing procedures involved, no interim estimates can be released even though the 225 minimum may be achieved after 12 but before 24 months.
•If this target of 225 unweighted AIR participants is not achieved after 24 months, no estimates will be released.