A Solution

 

Reviewing the various solutions that have been proposed over the years, it became clear that an abstract design would work best across cultures and applications.

However, being abstract, people would need to be educated on the symbols before being able to read them.

This is not a major issue – all symbols, even the ubiquitous arrow used to signify direction, need to be learned.

That said, the more the new symbols tapped into pre-existing concepts used in visual communications, the easier they would be to learn and understand.

There are just two rules a viewer needs to understand in order to interpret the symbols:

The first rule is that the closer an object is to the viewer, the larger it appears.

Assuming both objects are the same size, the object on the right is closer.


Assuming both objects are the same size, the object on the right is closer.

The second rule is that a solid line indicates an object’s present state, while a dotted line indicates a possible, future state.

The object on the left is currently at rest but can move to the right as indicated by the dotted line.


The object on the left is currently at rest but can move to the right as indicated by the dotted line.

 

Based on the two rules explained above, the following symbols are easily derived:

Using PUSH as an example, if this appeared on a closed door, the large circle would represent the door at rest. The smaller circle with the dotted line represents the door’s future state after it has been pushed away from the viewer.

 
 

THE RULES
BASIC SYMBOLS
EXTENDED RANGE

It soon became apparent that the concept, with the addition of
arrows, could be extended to wide range of applications: