sculpture in the expanded field

Q1. What is the point of labeling sculpture in terms of marked or site constructed? It seems to me that all of it is just site-specific art, but because some people don't understand the sculpture, they need a label to tell them what the purpose of the sculpture is and does labeling the sculpture (ie marked etc) will people appreciate the art more because of that label?

Q2. For the most part I understand the Klein group diagram. I understand that certain components make up different types of art, but the aspect of the diagram that confuses me is the complex and the neuter. I am really not sure what it means to have a complex or a neuter. they don't really seem to have a purpose, so my question is what does the complex and neuter mean to the art? Does it add or take away anything from the artwork in question? What does it mean to have a complex or neuter?