common seeds

[Alex-Jordan]

This is an outline for a new feature I would like to work on (for dev/2.19). I want feedback on the outline before I dig in, in case there's a better way to do this.

Motivation

Sometimes I want to use WW for an assignment, and use existing problems, but I would prefer that for each problem, each student has the same seed. One situation for this is when using a proctored test, where I'm already satisfied the proctoring is guarding against copying. But later I want to manually review student answers looking for typos they made. And it would be nice for me if all students has the same seed.

Common Seeds option

In the Set Details page for a set, there will be a new boolean: "Common Seeds". If it is false, no change from current behavior.

If it is true, then each problem now has a "common seed" field. These are all randomly generated and pre-populated, but can be set manually too. There is a button to "randomize common seeds" and a button to "clear common seeds".

Homework

The student has their own seeds for each problem, but if the set has Common Seeds true and the common seed field was nonempty, then the seed that is actually used for them is the set-level common seed.

Tests

When a new test version is generated, then like normal, some seeds are generated for that student for that version for each problem. But if Common Seeds is true, those seeds will not be used. Instead, some sort of hash combining the template set's common seeds and the version number is used. So all students get the same "version 1", the same "version 2", etc. Unless in the interim the instructor clicks "randomize common seeds" and then student A's version 2 could differ from student B's version 2.

Note that this is creating unique seeds for students that would go unused. That is so that the instructor can elect to toggle off "Common Seeds" and fall back to each student having different random versions.

Looking for feedback if I have this outlined well, or if there are ides for a better way.