All sculpture must, in one way or another, somehow confront the issue of structure.
Structure is a literal reality but can also be understood as a visual state.
The engineering and construction of an object is a literal experience of structure. But the way different elements in a work are patterned and composed is also an issue of structure. Even randomness is a form of organization. On the other extreme, organization might be a random or unruled type of relationship. By visual analysis of other sculptures and by working with quick sketch models you should become familiar with how you can create a structured or unstructured effect.