The UK sample size is approximately 5,500 businesses (4,000 in GB and 1,500 in NI). The response rate is normally around 92%. GB businesses are identified as follows:
- Businesses which have previously reported R&D expenditure above a threshold (greater than £5.7m for the 2016 survey - referred to as "large R&D performers").
- The remaining businesses identified as (or potential) R&D performers (referred to as "smaller R&D performers") are allocated into strata using their employment and industry product group.
The businesses in group one were all selected and all received a long survey form. There were approximately 400 long forms sent to businesses in GB. Approximately 3,600 GB businesses were selected from group two and were sent a short survey form.
The 2017 BERD Survey Form - Long
As part of the BERD 2011 ONS release, an information note was produced, which reports on the completeness of the BERD estimates, available at: Coverage of the Business Enterprise Research and Development Survey.