Wikipedia gives us a great definition: "Abstraction indicates a departure from reality in depiction of imagery in art. This departure from accurate representation can be only slight, or it can be partial, or it can be complete. Abstraction exists along a continuum."
Non-objective compositions can be remembered by thinking "non-objective = no object, such as people, places, or things." These types of compositions often contain geometric and organic shapes.
Here are some student examples of non-objective compositions. My apologies for any disconcerting photographic angles, I had students take the pictures.
