NARPS model "group" origin

[rwblair]

Took me a minute to realize that "group" used here was coming from participants.tsv:

model-zoo/model-zoo/exhibits/narps/model-narps_smdl.json

Line 57 in bd80dba

"GroupBy": ["contrast", "group"],

I feel like this should be made explicit some where, in model or in documentation, but I'm not sure where.

[Remi-Gau]

Technically it is mentioned explicitly: https://bids-standard.github.io/stats-models/_autosummary/bsmschema.models.Node.html#bsmschema-models-node

field GroupBy: List[str] [Required]
The output statistical maps received from the input node are split along unique combinations of the grouping variables and passed to the model as subsets. If empty, all inputs are passed to a single model to fit. Reserved strings include: “run”, “session”, “subject”, and “contrast”. Any metadata field may be used as a grouping variable.

So explicit but definitely not obvious.

As a half measure we could add a "Description" field to comment this, since those are allowed without invalidating the model.

[adelavega]

I think in the accompanying notebook we can explain this, as this is an example of this behavior.