You can only evaluate work based on the work you've seen by others. This is were the challenge starts and ends. Art is nothing more than a contrast that either resonates with you or goes completely unnoticed by an equal to, or greater contrast. Two great words; Skeuomorph→ and Umwelt→. Our individual perceptions, in my opinion, lie somewhere between these two words. Ideas are greater than facts. The idea of contemporary art, is just that, an idea. It's art that happens in your specific lifetime and generally overlaps modern art as you get older, wiser and just generally experience more in your life. And while I myself tried explain it, art requires no explanation. Everything created that is not considered art, is an attempt to explain something.