Feature Request: Add possibility to mark choice options as optional

[Kathrin84]

Hi Tobi,

this request developed in a discussion with a teacher and from the use case it's kind of related to that one of issue #103.
Our teachers are quite unsure how many choice options for allocating all students will be needed. So the idea came up that options could be marked as optional with explanation that this option is not fixed. In this case students would know if they vote for this option, in allocation phase it could be deleted.

And then in allocation phase the algorithm could be run with and without the optional choices and the teacher could decide if they need to be taken or if they could be deleted.

I'm aware that this is close to the option to disable choices, nevertheless in this case the uncertainty of some choices would be transparent for the students.

Cheers,
Kathrin

[tobiasreischmann]

Hey Kathrin,
I think we need to rework the way choices are considered in the allocation.
Currently, the only way is to mark them as inactive or active. That's not very intuitive.
Your proposal is a good way to start here.
Cheers,
Tobias

[tobiasreischmann]

We could also combine this issue with #40 and #148.
An option could then be marked as optional and could be assigned with a minimum, optimal and maximum capacity. The algorithm could then try to calculate the best outcome considering the preferences of the user. Unfulfilled constraints such as:

• Unassigned participants with submitted ratings.
• Unfulfillable minimum/maximum capacities.

should be listed in an allocation summary.
We would need, however, a sophisticated fitness function, which solves the trade-off between capacity constraints and preferences of the participants.