Is there any way to make an ongoing rubric/evaluation tool in CANVAS, that the instructor could fill out weekly so the students could see this without creating a new rubric/ clinical eval tool each week?
Canvas really isn't set up to do this.
Sometimes things are technically possible don't sound so good when you figure out how you have to do it. I imagine this is one of those cases and would recommend rethinking the process. Decide what it is you're really trying to accomplish and why you think it would be best as a single assignment. Share that and we may be able to come up with a better workflow.
One technically possible way to accomplish what you asked for is to create a rubric that has that the criteria repeated for each week. If there were 3 items in the evaluation and it was a 15 week course, that would lead to 45 rows in the rubric.
Combining 15 weeks of information into a single assignment might have the opposite effect of what you think. It may makes it so hard for students to find anything that they're likely to not use it in the way that you intended it to be used. If you leave submission comments (because comments inside a 45 item rubric are unlikely to be found), then they all run together and students may get confused about what's recent and what's old.
It's also going to make it harder to do analytics and track students. Canvas does not understand partial submissions or partial grades. If this is a graded assignment and it's based on the rubric, then they're going to start off with a really low score since only the first week is going to be filled in. Canvas is working on analytics that will alert faculty as to students that may be in danger of not being successful and it doesn't know that it's only supposed to be partially complete.
If this is actually based students turning in things each week, then you definitely don't want to do this. At this point, students can only see the latest submission on assignments. Canvas is working on changing that, but it's not here yet. That means that students would not be able to go back and see what they have done. It is also going to mess students up if you have them submit something each week because it will look like they have already turned it in, so it won't show up on their to do list.
I strongly suggest trying to figure out what the issue you're trying to solve is and seeking an alternative solution.
Jane Hoesterey why not duplicate the rubric as an assignment (assuming the information is the same for all of the weeks that you need it.) You can then have this rubric as rubric, rubric copy 2, etc. This would help Canvas and be easier for you and the students to understand. Just a suggestion.
Retrieving data ...