Major derivatives decisions

[Lestropie]

The magnitude of introduction of derivatives into the BIDS specification is thus far limited to common derivatives, which are comparatively rudimentary. DWI derivatives in BEP016 may be the first large step forward in the support of derivatives. As such it may be responsible for setting a wide breadth of precedents in terms of the representation of derivatives, well beyond the specifics of DWI.

I am going to try to make this Issue a central enumeration of what I think are the major decisions to be made in this respect, with the hope of engaging those responsible for maintenance of the BIDS spec outside of the BEP016 team. Individual points will then be separated out into their own Issues to keep individual discussions clean. I'll add here issue numbers for each as they are generated, and the list may expand over time.

(I also acknowledge I've not been able to keep up with the evolution of BIDS and related discussions over the last few years, so please add relevant links if any of this is naive)

1. • Pre-processed MRI data: Remove "Preprocessed diffusion-weighted images"? #25
2. • Filesystem paths for diffusion models: Filesystem paths for diffusion models #32
3. • Storing non-conforming derivatives in a BIDS Derivatives structure: Storage of non-conforming derivatives #33
4. • Location of demonstrative examples: Locations of demonstrative examples #34
5. • Location of format specifications (e.g. SH being applicable beyond DWI derivatives): Broadly applicable data representations #35
6. • Handling literature citations: Literature citations #36

[Lestropie]

@bids-standard/bep016: This is I think all of the main ones that have been plaguing my mind. If you don't have any additions or other suggestions, we should discuss these to the extent we can internally, and then some time in the future I'd like to broadcast this Issue more broadly, as much of it is consequential beyond BEP016.

[francopestilli]

From our in-person discussion, which one of the case be addressed by us?

[francopestilli]

4. We will do here.
5. We propose to postpone, not to be addressed now. We will find a solution and if anyone else later wants to discuss we can. If other specs need SH they can look at our and propose changes.

[arokem]

On some further discussion with @francopestilli and @Lestropie, we are thinking that maybe these divide into two groups. The following can be addressed here, and the solution can be proposed as part of the process of approving the BEP: 1,4,5 (essentially punting on 5).

The following should be raised as issues for discussion on the main spec: 2,3,6.

[Lestropie]

The main specification is currently under a release development freeze; perhaps after that is completed we should ping the BIDS maintainers, whether here or to a subset of such.

[francopestilli]

Hi Robert can you please clarify for me the ending of your comment? I'm having hard time parsing.

[Lestropie]

As in, if we are to get the maintainer's attention, we should decide on to what to draw their attention; e.g. perhaps instead of bringing them to this specific issue, we should instead just focus solely on #32.

[francopestilli]

Thanks for clarifying!