Regarding this question:

Is get_fitted_params the right place to return those? maybe a similar function e.g. get_fit_results is more appropriate.

A very valid point - do we want to separate fitted parameters from things like summaries or inspection?

The MLJ package, where I've co-designed the interfaces, does separate this, and I think it's a good idea - see
https://alan-turing-institute.github.io/MLJ.jl/stable/machines/#Inspecting-machines

During the dev days later this month, we'll probably refactor the interfaces, and this may be one thing we add - feel free to join.
I've also opened an issue #944 so we don't forget.

@mloning, have you had a look at this?
This affects the relatively new get_fitted_params interface, would like to have a 2nd opinion.

I agree @fkiraly, fitted parameters are different from summary statistics of the model, so suggest to create a separate interface for them.

Thanks @mloning and @fkiraly. I think this is the right call, it felt wrong to put AIC etc. in the same place as the fitted model parameters. Do you think I should keep going with this PR and implement the function to get summary statistics here? or is it more appropriate to do it in a separate PR (maybe linked to #944 ).

I suggest to work on the interface first in a separate PR, before we start adding it to concrete implementations.

hm, @mloning, I would suggest we merge this and then perhaps later move it to the other interface - or this nice contribution may be buried under refactors and commits on top?

Rationale being, moving it from get_fitted_params to get_report_params or similar is almost trivial once we have the interface point, while finding the PR again, updating it, and remembering to do this later may not be easy.

2 approvals, so can be merged now.

@ltsaprounis, I think @mloning and I have aligned that we'll merge this and then later re-factor along #971.

Would you like to merge?
Minor suggestion, please add the names of the classes you've changed in the squashed commit message.

merged due to dependencies and 2 approvals

Sorry @fkiraly I was on holidays for the past few days and nowhere near my laptop. Just realised Github has an "out of office" option...

Looks good to me, thanks for merging!