Data processing and outline
Weighting
Rim-weighting by:
- Gender within age group (x8 age bands up to 75+ – with 15-24 split into 15-17 vs. 18-24)
- Gender by age band (x7) within area grouping
- Gender within 60 PAMCo weighting areas
- ACORN sampling band (x7) within London GOR and rest of GB
- Terminal Education Age
- Household Size
Further details of the weighting procedures are available from Ipsos MORI.
Ascription Procedure for Daily Newspaper
Commencing in July 1994 an ascription procedure has been applied to Daily Newspapers.
The tables show results for three AIR measures as follows:
Monday-Friday average issue readership (5 day AIR)
Saturday issue readership (Saturday AIR)
Monday-Saturday average readership (6 day AIR)
Monday-Friday average issue readership (5 day AIR)
The PAMCo interview asks about Monday-Friday readership of daily newspapers and Monday-Friday AIR is captured directly from the interview data and not ascribed.
Saturday issue readership (Saturday AIR)
These are obtained from a specific question on the readership of Saturday issues of national daily newspapers.
Monday-Saturday average readership (6 day AIR)
AIR targets are calculated from 1/6 of the Saturday (‘Yesterday’ or ‘Past 7 days’) and 5/6 of the Monday-Friday (‘Yesterday’) AIR.
The ascription procedure was modified in April 2014, so that the aforementioned 5 day and 6 day adjustments were applied to the AIR in Government Office Region Scotland separately from the AIR for the rest of Great Britain, for 4 national daily newspapers (5 from January 2017). These are newspapers which have a different masthead for their Scottish editions: Daily Express, Daily Mail, Daily Star, The Sun (and The Times from January 2017).
Adjustment for Circulation Loss
In addition to the demographic weighting, results are adjusted for the effects of circulation loss where there has been interruption of normal publication. The adjustment procedure involves changing the codes of some participants from ‘non-reader’ to ‘reader’ for a relevant title.
Details of the current adjustment procedures, which have been applied since January 1988, can be obtained from Ipsos MORI.
Estimates of circulation loss are based on data reported to the NMA or PPA by each publisher together with ABC information concerning National Newspapers. Non-members of the NMA and PPA report directly to Ipsos MORI. The completeness and accuracy of these data is thus beyond PAMCo Ltd’s direct control.
24 Month Base Procedure
The extended base procedure (previously known as the 24 month base procedure) allows smaller titles to have PAMCo published estimates. The procedure is applied to titles falling below the publication threshold of 100 unweighted average issue readers (AIR) in the standard reporting period but achieving an unweighted AIR of 100 or more over a period that includes the standard reporting period and the previous 12 months.
The procedure combines data from the standard reporting period, including the current quarter, combined with the previous 12 months of data, to calculate the combined penetration of each of the recent reading and frequency of reading claims in the total population. These penetrations are then applied to the total population for the current quarter to set targets for adjustment. This may have the effect of adjusting read past year (RPY) as well as AIR.
A summary of the procedure for adjustment is as follows:
- On an annual basis, identify and specify publications that qualify for this procedure.
- Combine audiences for the most recent reporting period and the preceding 12 months of data.
- Calculate new AIR and RPY targets from the combined population penetrations for frequency and recent reading.
- Adjust weighted data for the current quarter, according to the targets. Randomly select participants to add from the ‘non-reader’ population, or to remove from the reading population. Selection is based on a target demographic profile, created from the combined quarters’ data.
