Sign saturation is a common problem in busy public spaces. You find yourself simply swarmed by signs not knowing where to look. This is particularly evident if numerous entities want their sign to stand out from others. The beholder can become easily lost in the battle of the signs.

The positioning of signs poses another problem. Where is the best place for a sign to be easily noticed and the information quickly taken in? Signs are often placed too high up - we must bend our heads at an angle that does not come naturally, or we simply miss them all together. It is, in fact, much more natural for humans to look straight ahead and down rather than up - our ancestors hunted on the ground and looked for ground predators far more than sky predators. That said, the Eurostar at St.Pancras in London has useful, detailed signs carefully stuck on the ground indicating carriage numbers and directions, but most passengers (myself included) search for hanging signs instead! Both our innate and learned habits play a part in our receptiveness to signs.

Some signs we encounter are simply unclear. I recently spent quite some time with friends discussing the signification of a particular road sign - featuring a symbol of a caravan with a triangle below, seemingly above a stream of water. Ultimately icons are an effective way of providing information, if they are clear! Perhaps the mysterious caravan sign is easily interpreted by caravan users, in this case it is not necessary that it be understood universally.

If signs are for multiple audiences it is important that the sign be understood by all target groups. The road sign above, from bi-lingual Wales, was evidently checked only by an English speaker. The Welsh reads: "I am not in the office at the moment. Send any work to be translated."

Colours can make signs stand out or can group or prioritize certain signs over others. The key here is that the signification of particular colours is clear. In Geneva airport, the division of signs into yellow (for all flight related information- security, gates etc.) and white (for everything else - shops, food halls etc.) is unexplained and often misunderstood. Similarly, colours may signify one thing to some people and another to others. Take road signs - in France blue is for the motorway, and green for other roads. In neighbouring Switzerland it is the opposite.

For the sign-reader to find their way easily they can only hope that their needs were at the heart of the planning stage. Signage needs thorough thinking through, a strategic approach and certainly an understanding of different aspects of perception analysis that affect where we look (and why), how we react to a sign and it’s surroundings and how we interpret the total of what we perceive.

In a public place it is useful for signs to be coherent and to work as a system. If there is a priority path (i.e, from the check-in to the gate) this should be clearly differentiated so people don’t get lost in a maze of other information.

On a business note, to communicate in an environment of information overload, a message needs to be visible. There are many perceptual factors to consider to really stand out from the crowd.

On a personal note, unclear signs are now a source of interest and often amusement. Unless of course, I'm lost and in a rush!