One of the things that led me to standards-based assessment is Universal Design for Learning. I believe deeply in multiple avenues of expression. UDL was and is very hard in a traditional grading system. Student A wants to create a presentation, Student B wants to write a poem, Student C wants to make a movie. That's at least 3 different rubrics. Plus, there were inevitably projects that were high on creativity and presentation, while low on content. Every time a student wanted the ability to express himself or herself, it meant a ton of work for me. Plus, every once in a while a student would want to do something so different I really had no idea what I wanted it to look like. The major problem with this system is that rubrics focus on the assignment. What it should focus on is the learning.
Now, I have my topic scales. Everything can be evaluated against that scale.
What knowledge did you demonstrate? Well, it looks like you included the 2.0 standards and partially demonstrated your 3.0 standards. This poem/powerpoint/interpretive dance is a 2.5.
Last year's final was simply,"Demonstrate your knowledge of one of the topics from this year in any way you like." There were a few restrictions for ethical and legal reasons and I required something physically, or digitally, turned in (dances and songs could be recorded). I got a video on the forces involved in archery, a group of girls dancing the different states of matter, an animation on how to solve motion problems, a couple of rap songs, a lot of soccer videos, a couple of photojournals, and yes, even some essays.
One more thing I should point out. My problem with multiple avenues of expression was always that certain methods seemed a little....soft. Instead of having them write an essay, you want me to let them draw a poster? That's not the same thing at all.
Now think about when it's evaluated against your topic scale. How hard would it be to state ALL three Newton's laws and apply them to real life situations in a rap song? There is no soft option because the exact same level of knowledge needs to be demonstrated regardless of how it's done.
Next time you're designing a rubric for an assignment, think about what learning you would like to be communicated. Design your rubric for learning and you'll have something that is not only more flexible, but the focus will be on what has been learned rather than on the assignment itself.