OVERVIEW OF GESTALT:
Gestalt is a general description for the concepts that make unity and variety possible in design. It is a German word that roughly translates as 'whole' or 'form'.
The study of gestalt originated in Germany in the 1920s. It is a form of psychology that is interested in higher order cognitive processes relative to behaviorism. The aspects of gestalt theory that interest designers are related to gestalt's investigations of visual perception, principally the relationship between the parts and the whole of visual experience. The visual world is so complex that the mind has developed strategies for coping with the confusion. The mind tries to find the simplest solution to a problem. One of the ways it does this is to form groups of items that have certain characteristics in common.
-paraphrased from http://daphne.palomar.edu/design/gestalt.html, accessed 23 Aug13
All image sources below are linked to the picture. To see its source, click on the picture.
One Gestalt concept is Proximity. We reviewed many more in lecture the second week of classes when we began Project 1.
PROXIMITY: When elements are placed close together, they are perceived as a group.
The example below shows 2 ways of organizing the six circles.
This is what is meant by "THE WHOLE IS GREATER THAN THE SUM OF ITS PARTS". In B, we see the whole (the grouping that forms a triangle in this case) more than we see each individual part (six separate circles).
The photo below groups the 2 individuals walking near each other and separates the one walking the other way. FYI: this sample shows both proximity (the 2 girls are close together vs. the guy) and similarity (girls facing forward, guy facing the other way) to group in order to simplify the visual world. Instead of individual squares or people, our mind perceives separate groupings of individual things. We can still see the individual pieces, but our mind helps us to simplify our world by grouping. "THE WHOLE IS GREATER THAN THE SUM OF ITS PARTS."
Though many Gestalt principles will overlap, be careful to not confuse Proximity with Similarity. For example in the photo below, the gentleman facing forward vs. those around him group by similarity (or one could think "he is facing the other direction, and is therefore DISsimilar from others around him"). However, they are all in one big group, so it doesn't illustrate Proximity very well.
If you get confused, try to imagine the items in the picture (people, nature, buildings, letters, etc.) as the simple squares vs circles. The guy facing you would be a circle surrounded by those around him as squares. The squares would group by similarity vs. the circle, but the proximity has no play here.