Data Quality in e-RA

In accordance with the Joint Code of Practice for Research at Rothamsted, data processing in e-RA follow rigorous standard operating procedures to ensure the quality and correctness of data collected in the field through to depositing in the e-RA database. Full details of the Standard Operating Procedures (SOPs) followed to ensure data quality control can be obtained from the e-RA Curators.

Sample collection procedures

Standard Operating Procedures are followed for sample collection by combine harvester, sample processing, dealing with harvest samples and preparing them for analysis, and details of additional samples from the Classical Experiments to be kept for archiving.

Data checking procedures

Until 2019, to ensure quality control during data inputting, the data sets were typed on two separate occasions (double data entry). During the second typing (verification) the data values were compared with those typed on the earlier occasion, and any discrepancies were resolved before verification continued. This procedure also set out how to handle situations where the written records were illegible or ambiguous. This procedure avoided visual checking of data, which can be very inaccurate. Once the data are entered into e-RA, they were independently back-checked against the original data sheets. They are also subject to consistency checks embedded within e-RA.

Since 2020, there is no longer any routine manual data entry, as most records are now in electronic form. New datasets, and annual updates to existing datasets, are independently back-checked with the original data source. They are also subject to consistency checks embedded within e-RA.

Downloading meteorological data

Standard Operating Procedures are followed for downloading the meteorological data from Rothamsted, Woburn and Brooms Barn automatic weather stations. The calculations of the derived variables are by standard formulae, embedded in e-RA (see derived variables). There is also a SOP to follow for measurement of precipitation at times of snowfall (turf wall enclosure), as heavy snowfall can block the ARG100 rain guage.

Quality control of meteorological data

All equipment, including the datalogger, is checked, serviced and calibrated annually at Rothamsted, Woburn and Brooms Barn by Campbell Scientific Ltd. The Test Equipment used in the Campbell Scientific calibration/maintenance process are registered on an in-house Calibration/Maintenance database. The Test Equipment is either calibrated to National Standards by a UKAS accredited laboratory, or are calibrated in-house using instruments which have themselves been calibrated by a UKAS accredited laboratory. Hence, all equipment calibrated/maintained by Campbell Scientific Ltd is traceable to these standards.

The data are also subject to consistency checks embedded within e-RA.

For further information and assistance, please contact the e-RA curators, Sarah Perryman and Margaret Glendining using the e-RA email address: era@rothamsted.ac.uk