Gestalt Laws
Gestalt laws describe regularities of human perception (but do not explain them!)
Proximity: objects that are close to each other tend to be seen as a group
Similarity: objects of the same shape or color are seen as belonging together
Closure: Missing parts of an object are filled in to complete it, so that it appears as a whole.
Continuity: lines tend to be seen as continuous, even if they are interrupted
Symmetry: regions bounded by symmetrical borders tend to be perceived as coherent figures