Returns are records of original work done by researchers using project data which have been made available for use by other researchers when their project completes or reaches agreed milestones. Contents can include any or all of source code, derived data and methodology notes. The contents of Returns are only available to researchers on approved Applications, and access to certain archives are restricted further if they were derived from data which was itself restricted.

The quality and integrity of returned data is the responsibility of the researchers who generated and supplied it. No central quality control checks are performed on returned datasets prior to making them available to other researchers, although we try to ensure that contents including derived data also include the code required to generate them and researchers are encouraged to perform their own review to confirm that the data meet their quality requirements. Queries concerning returned data should be addressed either by referring to the linked publications or by contacting the originating researchers directly.

Note that, as a small number of participants withdraw over time, it may not be possible to precisely replicate original results given a up-to-date dataset.