I'm building an editor for multiple choice questions. Question can either allow a single chosen answer by the user (radio buttons) or multiple answers (checkbox).
Each choice has a percentage value that describes its "correctness", for example, in a radio button question, you get all the points if you select a choice that has a value of correctness equal to 100%.
The editor looks like this:
What I don't like about this editor is the fact that the user has to manually input percentage values, which comes with a high interaction cost: in most cases, the user only wants to be able to mark the correct answers as such, so having a checkbox with a label "Correct" next to the answer's text editor would be much better.
At the same time, some users do want to have control over "partially correct answers" (for example giving 50% of the score rather than either 100 or 0) or even give negative score.
While, for radio button questions, it's easier to reason about correctness of a choice (a choice is correct if it has a score value of 100%, partially correct if it's anywhere in between 100 and 0, and incorrect if it's 0 or lower), with checkbox questions, there is an additional difficulty: you get the maximum score if you select all and only of the "correct" choices, which means that the correct choices' correctness values must add up to 100%.
So, for radio buttons, you might have a checkbox that allows to quickly select the correct choices and automatically set their value to 100%. But, for checkbox buttons, setting a choice as "correct" also changes the value of the other correct ones, in order to keep their sum equal to 100.
For example, if I marked a choice as the correct one for the first time, it'd have a correctness of 100. But marking a second choice as correct would give them both 50% correctness.
What would be a good way to simplify the interaction with the editor and allow: (1) for most, simple use cases, to directly mark the correct answers as such and, (2) for users that want full control over the correctness values, to still allow for such advanced usage?