SIDECAR_KEY_REQUIRED not documented

[jens-k]

I ran the BIDS validator on a super simple dataset (one subject, one session, just for testing) and got the error "SIDECAR_KEY_REQUIRED (SoftwareFilters)".

I cannot find any information about this issue. The validator provides a link but (as for any error or warning I have ever encountered), the content behind the link seems unrelated to my issue or too cryptic to make sense of it.

I therefore tried to look for "SIDECAR_KEY_REQUIRED" and "SIDECAR_KEY" (which is the type of error, so it should be way more common than the particular one I got about software filters) on the following websites:

• BIDS specification (https://bids-specification.readthedocs.io/)
• BIDS Manual (https://bids-standard.github.io/)

I have no hits for any of the terms. As this seems to be an entirely undocumented requirement/tag/error, I thought this might be considered a bug. I found a cryptic description of "SoftwareFilters" here: https://bids-specification.readthedocs.io/en/stable/glossary.html#softwarefilters-metadata but a normal user cannot be expected to understand this schema, and it does not fit to how I solved the problem.

The answer the user should get is:
In the sidecar file "*****.json", we would have expected a key called "SoftwareFilters". This key is specific for the eeg datatype. You can fix the issue by adding another line
"SoftwareFilters": "anystringiguess",
to the json file.

Is there an effort to fix these error messages? If so, I'd be glad to contribute.

[github-actions]

Thank you for your issue. Give us a little time to review it.

PS. You might want to check the FAQ if you haven't done so already.

This is an automated reply, generated by FAQtory

[Remi-Gau]

Hey @jens-k

Thanks for the report.

This metadata is also mentioned in the tables for the required metadata for EEG, ieeg and MEG.

https://bids-specification.readthedocs.io/en/stable/modality-specific-files/electroencephalography.html#sidecar-json-_eegjson

Though I admit those hits were at the bottom of the search when putting SoftwareFilters in the search bar of the bids specification.

For the improvement of the error message I think you should probably reopen this issue in the repo of the bids validator.

[Remi-Gau]

Will transfer the issue to the BIDS validator repo.

[effigies]

You should see: "A data file's JSON sidecar is missing a key listed as required."

What error are you actually seeing?

[jens-k]

"SIDECAR_KEY_REQUIRED (SoftwareFilters)"

[effigies]

Oh, it doesn't even tell you what files that's happening in? Could you share a screenshot of the expanded error?

[jens-k]

Sorry, we moved on with that project and I don't have the files anymore in the version that produced this error. In the end, we used the validator of openneuro to check the dataset, which gave us more information about each error and we were able to fix them swiftly.

If I had to summarize my experience with the bids-validator, I would say that I just did not receive the information I needed as a rather casual user to fix the problems and not in the language I could understand. Forwarding me to a forum on another website did not help me either.

Nevertheless, thanks for your response and the work you are doing!.