Performance and product based assessment

Where would performance-based assessments fit in your world? Where would product-based assessments fit? I really like this question. I love performance based assessment and product based assessment because that is what I primarily use in the art field. For a performance based assessment I have the students learn a technique or skill that I would be looking for in a piece of art like symmetry or texture. I show the students how the technique is carried out in pencil, paint, or clay. Lets say I am looking for texture in an assignment. I show the students visual texture (texture that is seen) and tactile texture (texture you can feel) and explain how they differ. I have the students draw texture....shiney, slimmy, sharp, pointy,etc (visual) and then I have them use texture plates or rubbings to actually feel the texture (tactile). I ask them to demonstrate each method and describe the differences to me orally. I then ask them to produce 2 pieces of art, 1 being visual and 1 being tactile, and then explain them to the class. Most of the methods I use involve a performance or product based assessment. It is when I use the formal assessment in tests that I find difficult, as well as the students do. I believe if they can explain the process and show a completed piece, then they have learned the technique or objective that I have laid forth for them.