Hack75.Grasp the Gestalt


Hack 75. Grasp the Gestalt

We group our visual perceptions together according to the gestalt grouping principles. Knowing these can help your visual information design to sit well with people's expectations.

It's a given that we see the world not as isolated parts, but as groups and single objects. Instead of seeing fingers and a palm, we see a hand. We see a wall as a unit rather than seeing the individual bricks. We naturally group things together, trying to make a coherent picture out of all the individual parts. A few fundamental grouping principles can be used to do most of the work, and knowing them will help you design well-organized, visual information yourself.

8.2.1. In Action

Automatic grouping is such second nature that we really notice only its absence. When the arrangement of parts doesn't sit well with the grouping principles the brain uses, cracks can be seen. Figure 8-1 shows some of these organizational rules coming into play.1

Figure 8-1. Two groups of triangles that point different ways and a middle triangle that can appear to point either way, depending on which group you see it being part of 2


You don't see 17 triangles. Instead, you see two groups of eight and one triangle in the middle. Your similarity drive has formed the arrangement into rows and columns of the shapes and put them into two groups: one group points to the bottom left, the other points off to the right.

Each group belongs together partly because the triangles are arranged into a pattern (two long rows pointing in a direction) and partly because of proximity (shapes that are closer together are more likely to form a group). The triangle in the middle is a long way from both groups and doesn't fall into the same pattern as either. It's left alone by the brain's grouping principles.

You can, however, voluntarily group the lone triangle. By mentally putting it with the left-hand set, it appears to point down and left along with the other triangles. You can make it point right by choosing to see it with the other set.

8.2.2. How It Works

The rules by which the brain groups similar objects together are called gestalt grouping principles in psychology. Although there's no direct German-to-English translation, "gestalt" means (roughly) "whole." When we understand objects and the relationships between them in a single, coherent pattern rather than as disconnected items, we understand the group as a gestalt. We have a gestalt comprehension of each of the sets of triangles in Figure 8-1, for instance.

Four of the most commonly quoted grouping principles are proximity, similarity, closure, and continuation. An example of each is shown in Figure 8-2.

Figure 8-2. The four most quoted gestalt grouping principles



Proximity

We preconsciously group items that are close together, so in the picture you see columns rather than rows or a grid. This principle is the cause of the triangles in the original diagram coming together into two sets and the reason the lone triangle didn't feel part of either of them.


Similarity

We prefer to group together objects of the same kind. In the example, you see alternating rows of circles and squares rather than columns of mixed shapes.


Closure

There's a tendency to complete patterns. There's no triangle in the example pattern, but we see one because the arrangement of the three Pac Man shapes would be completed if one were there.


Continuation

Just as we like to see completed patterns, we like seeing shapes that continue along the same path, smoothly. We see two lines crossing in the example, rather than two arrowheads touching at their points or four lines meeting together.

When none of these principles apply, it's still possible to mentally group items together. When you put the middle triangle in Figure 8-1 with one group or the other, it picks up the orientation of the group as a whole. It's a voluntary grouping that modifies how you see.

Gestalt principles exist in visual processing not because they are always right, but because on average, they are useful. They're good rules of thumb for making sense of the world. It's not that similar things can't be separate; it's more that most of the time they aren't. Although random coincidences can happen, they are vastly outnumbered by meaningful coincidences.

The world isn't a mess of disconnected parts, and it's useful to see the connectionsif you're hunting an animal, it makes sense to see it as a single gestalt rather than a paw here and a tail there.

8.2.3. End Notes

  1. The gestalt grouping principles are interesting, but are they really useful? Good print or web page design involves easy comprehension, and knowing how the principles can conflict or mislead in your layout helps along the way. James Levin has applied the gestalt grouping principles to web design (http://tepserver.ucsd.edu:16080/~jlevin/gp).

  2. Illustration inspired by Fred Attneave's demonstrations as used in "How the Mind Works" by Steven Pinker.

8.2.4. See Also

  • Max Wertheimer was the first to identify the principles in his 1923 paper "Laws of Organization in Perceptual Forms" (http://psy.ed.asu.edu/~classics/Wertheimer/Forms/forms.htm).

  • As well as the basic grouping principles, which work looking at static objects, others deduce grouping from behavior over time [Hack #76] .



    Mind Hacks. Tips and Tools for Using Your Brain
    Mind Hacks. Tips and Tools for Using Your Brain
    ISBN: 596007795
    EAN: N/A
    Year: 2004
    Pages: 159

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