Ambiguous Visual Controls

Ambiguous Visual Controls: When Words Aren’t Necessary

By Jon Miller Updated on May 18th, 2017

Visual controls must by definition be clear indicators of normal versus abnormal, go versus no go, okay versus not okay. The sign above isn’t at all bad compared to other ambiguous visual controls we’ve featured here, here and here in the past.

It’s classified as ambiguous for several reasons. First, the human figure in the sign seems to be more than simply walking. There is a jauntiness, as if about to break into dance. What does the sign ask us not to do? Presumably walk or enter the area near the sign. The second element of ambiguity, unfortunately was not captured so well in my photo. There are at least 5 distinct areas near the sign which could be considered “off limits” or “no entry” zones; A) the grass, B) the rain gutter covered by 12-in slabs of concrete, C) the hedge row separating the rain gutter from the walkway between factories, D) the red path to the hydrant, and e) the narrow path from path C to the road.
From another angle a sign is visible about 15 feet away from our ambiguous visual control. It is on the other side of the path connecting the road to the walkway between factories. If you can read Portuguese, this adds some clarity but does not remove all ambiguity. In between these two signs, separated by some distance is what looks like a perfectly reasonable walking path, about 4 feet wide. This path is apparently used for forklifts, carts and material handling devices and not as a walking path for people. This is not immediately clear since by the time you are reading the sign, you may be well on the forklift path, or even walking from the road towards the factory walkway, seeing only the backs of these signs.

Words aren’t necessary when unambiguous visual controls are used. For example, this one clearly says “no playing soccer”.

Planning to drop a cushion and lounge for a while? Clearly prohibited.

And anyone planning a historic reenactment of a medieval battle would be disappointed by this sign.

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