Group level behavioral data and BIDS

Does the BIDS format accommodate group-level data?

In my particular case, I have surveys that were completed together by groups of participants. The BIDS spec focuses on the subject level, and doesn’t include (so far as I can see) recommendations for how to handle group level data.

My current thought is to duplicate the data in a group session for each participant, e.g.: “/sub-sid000/ses-group/sub-sid000_ses-group_task-survey_beh.tsv”. But I worry that the data duplication could cause confusion or errors down the road—it would be best if the data could live in a single, unambiguous location.

Thanks for bringing this up. Indeed this particular use case is not well supported by BIDS. I think duplication in this case might be inevitable.

BTW If this is truly a survey and you are recording item level responses this data should go into /participants.tsv or if you want to split it into multiple files, into /phenotype folder. See http://bids.neuroimaging.io/bids_spec.pdf#page=46 for details.