It often depends on the type of art that the teacher was looking for. For example, if a ceramics teacher was looking for a coil pot, often times they will just hand out a rubric. Typically the requirements on art rubrics are loose- otherwise everybody's work would end up looking identical. For example, one requirement could just be "a couple rows of different coil designs" for a coil pot for full points on that assignment. Art teachers also grade based on a self-reflection form students may fill out. For more abstract pieces, the teacher might just grade based on why the student designed their artwork like that.
Hope that helped you.
Aperture is controlled by 'diaphragm' in optics.
<span>The film industry didn't care about it looking more realistic to show films in anything other than black and white. Black and white was what people were used to therefore, they thought it looked more realistic. It was also cheaper to make films in black and white.</span>