Gestalt - A German word that roughly translates as "whole" or "unified whole." Gestalt theory of visual perception was developed in the 1920s and describe the visual tendency to create groups. Gestalt emphasizes the relationships of shapes to the whole. The Gestalt principles are closure, proximity, similarity, continuity, and common fate.
Closure - Closure is a Gestalt concept the refers to the visual tendency to create closed shapes even when part of the shape is missing. Closure bridges gaps in shapes and implies a complete shape.
Closure with gaps in lines.
Closure with gaps in shape.
Dog Lying in Snow
Closure with gaps in shape.
Proximity - Proximity is a Gestalt concept the refers to the visual tendency to group shapes together if they are close to each other. The group will generally be perceived as a single unit.
Proximity is relative to the number of shapes and the context of the shapes. In this example, one would probably describe it as an image of two shapes (cones).
It does not exhibit good proximity.
In this example, one would probably describe it as an image of two groups.
It exhibits good proximity.
(note: proximity does not require identical shapes, as in the group on the right)
Proximity in grouping of houses.
The Raft of the Medusa
Groups of people based on proximity.
(note: there are more groups present than the two identified above)
Similarity - Similarity is a Gestalt concept the refers to the visual tendency to group shapes together if they visually resemble each other. The shapes do not have to be completely identical. The group will generally be perceived as a single unit. Typically, similarity also requires some amount of proximity (see proximity above).
Similarity creating five groups.
Similarity of shape creating one group.
The figures highlighted in yellow are in close proximity but do not seem to create a
group because they lack good similarity.
The figures highlighted in green are in close proximity and exhibit good similarity.
Continuity - Continuity is a Gestalt concept that refers to the visual tendency to create continuous figures. Continuity is most commonly (though not exclusively) exhibited in the perception of lines and refers to the tendency to "carry the line forward." More specifically, there is the tendency to continue smooth figures forward over abrupt changes in direction.
Continuity describes the tendency to see the left figure above as two curved lines.
The right figure illustrates the two curved lines, one red and one blue.
While the above illustration is one possible perception of the previous example, continuity describes a tendency for smooth figures over abrupt changes in direction. This example exhibits abrupt changes in direction at the intersection of the two lines.
Continuity also describes grouping. The figure above is generally perceived as a line rather than individual circles.
Good continuity is exhibited in the shapes to the right.
Vertigo, Magic Staircase
The figure of the woman is perceived as a shape separate from the curve
of the staircase due to continuity.
Common Fate - Common fate is a Gestalt concept the refers to the visual tendency to group shapes together if the shapes move in a similar direction. The shapes do not have to exhibit similarity or exhibit proximity.
Before playing the animation, examine how groups are perceived.
The circles create one group due to similarity and the squares to the right create a second group due to similarity. All of the figures can be perceived as one large group due to proximity.
Now play the animation and examine how common fate alters the previous sense of grouping.
Look at the image above and determine what would be a group, then watch
the animation below.
Pausing the animation at almost any point makes it difficult to distinguish groups. However, when motion is visible and common fate is exhibited, a group of orange circles becomes apparent.
Common fate allows the perception of figures that would be imperceptible without motion.