How does the sample work?
Parliament set out detailed rules for the administration of PLR in the PLR Scheme (1982). Because it would be expensive and impracticable to attempt to collect loans data from every library authority in the UK, it was decided to employ statistical sampling methods instead. The original sample comprised only 16 individual branches – but this has been expanded over the years and we now collect data from a minimum of 30 library authorities covering around 1,000 individual branches. For the purposes of PLR, the country is divided into eight regions into which library authorities are grouped. We must include a minimum number of authorities in each region.In recent years we have seen the emergence of local ‘community’ libraries set up by independent groups and managed outside the local authority public library service. Under the PLR legislation these community libraries cannot be included in the PLR library ‘sample’. Only public libraries operating as part of the statutory library service provided by local authorities under the 1964 Public Libraries and Museums Act qualify for PLR. More information is provided on the GOV.UK website.
We have to be mindful of costs as whatever we spend on sampling reduces what is available for payment to authors. We are obliged by law to reimburse the library authorities for the costs of installing the PLR software and providing us with regular updates of loans data. As technology gets cheaper and more sophisticated we have been able to collect more data at no increased cost and we will continue to look out for opportunities to expand the sample size by using shared library systems etc.
How are loans grossed-up?Because PLR figures are derived from a representative sample of library authorities, a grossing-up calculation is applied to the actual loans at the end of each PLR reporting year, in order to provide a national estimate of loans for the whole of the UK and Northern Ireland.
If you require more in-depth information regarding this process, please contact the PLR Operations and Marketing Manager.
How long would a library authority stay in the sample?
To ensure fairness and accuracy at least seven of the authorities are replaced each year and no library can stay in the sample for more than four years. The PLR Operations and Marketing Manager will always consult with authorities prior to their being designated as sample libraries and at least six months formal notice of participation is given.Costs incurred by a library authority in the collection of this data are reimbursed by the PLR office.
What would being a sample library involve?
A designated sample library authority must provide the requested data, usually for a period of four years. Further information can be found under Information for UK sample library authorities.