I disagree strongly to the idea that art is not a "core subject." It is that perception in education that relegates us to peripheral status, filler, and an easily cut program when budgets get tight.

I also disagree that we should not "test" students in the traditional sense. To no do so separates us from the rest of the school, gives the impression our subject is not worth testing, and that we are somehow less important. We can have a separate discussion about testing and how valuable it is or is not--I'd prefer NEVER to have to test my students, BUT it is the reality within we live and work. (That may change but let's stick with reality)

...and what is wrong with testing vocabulary terms like in an English class? Shouldn't we test the historical knowledge we have passed on to our students like they do in history classes? If we use rulers, would it be unusual to do an assessment on measuring? What we do in art can and does support all other curriculum... if you allow it to.

I'd argue that art is THE most important core subject, helping all other subjects make more sense at a deeper experiential level. It's why art students score 100 points higher on things like the SAT. 

I believe we should not test for "creativity" or "prettiness," but we should grade and assess vocabulary, elements, principles, and where appropriate, the core concepts we incorporate into our lessons.

When we grid, measure, and draw—we use geometry. When we make sculptures—we use engineering. When we mix colors—we reveal information about physics. When we create illustrations for stories—we learn about literature. When we review the styles of art from da Vinci to Bansky—we teach history. When we write about art—we strengthen these skills. When we create works of art, we solve complex visual problems in creative ways. Art is the meeting place of all subjects. 

I won't bore anyone with more, but you can read a bit more HERE.

Looking for assessments? Free ones HERE, others are HERE.

I consider myself a modified traditionalist in my approach to art education. We explore art one project at a time. I create the scaffolding, and students must fill in with their own life of bricks, stone, stucco, etc... so to speak, ensuring an original and personal project. They must make choices that personalize their work, and in my mode, the work must be tied to core content in some way. (Math, Science, History, Literature, Writing.)

TAB= Teaching Artistic Behavior, some call it "CHOICE" based art education. It's pretty prevalent in elementary schools, but rarer as you move up to higher grades. It often involves stations where students explore different media and themes at their own pace with many different projects happening at the same time, with the teacher as facilitator. Students clean up their own materials, record their daily work, and often end sessions by sharing their results with the class.

Though "stations" would not work in my room, I have already introduced a unit where students get 12 choices to explore, and all my projects include an element of choice, (Plus connections to core content which is another discussion...)

A discussion I posed in the Facebook Art Teacher's group, and my own previous experience with my 12 choices project, has inspired me to add a bit more choice than I already do for certain units, like portraiture.

I can easily make packets of many different ways I have approached the subject over my 25 years... blind portraits, gridded ones, traditional proportions approach, portraits with expressive color and pattern, linear ones where the hair tells a story about the person, and many more. Usually I choose one approach for all and they have to personalize it with their own choices of what to include to show off who they are, but by opening it to many approaches they can explore a bit more broadly, and I can still monitor without feeling overwhelmed. 

Explore Ian Sands Apex Art Choice Program Art of Apex H.S.

Below are several portrait-based projects I have done over the years...