November is just around the corner, and you know what that means: as you drive, your eyes will be visually accosted by an abnormally large number of small plastic signs on the side of the road. Oh yes, it is the height of election season. Political campaigns invest a significant amount of money in these signs each election year hoping to sway those undecided voters at the last minute, and yet I am always surprised at how much more effective these signs could be if the sign designers were to apply some basic principles of human perception and memory to their designs.

Visibility Matters
The first goal of a political campaign sign is to be seen. Many signs fail at this step, because they cannot be seen at all from a passing car — they blend into their surroundings. Although vision is the most powerful sense, humans are not great at noticing an object with the same primary color as its surroundings, particularly when engaged in another task like driving. The more distinct a color is from its surroundings, the better chances are that it is noticed. Therefore, consider the environment around a sign: most are placed close to the ground. This means it will be surrounded by greens, light blues, and browns. By selecting a color that is as different as possible from these surrounding colors, the sign “pops” from its surroundings, and the chances of it being noticed by a passing car increase. The best sign colors are usually dark, such as navy blue.

Another consideration is the location of the sign. Most of these types of signs are placed low to the ground. As election day approaches, more and more signs are posted, until there are so many they blend together. How can a sign stand out from such visual clutter? One solution would be to place the sign higher than the others, or make the sign a different shape from the others.

Legibility — Once you see it, you have to be able to read it
Once a sign can be seen, its next goal is to be legible from a passing car. Once you have selected the sign’s background color, you’ll need to decide the color of the text on the sign. We can apply the same principle as we did when selecting the background color: select a color that is as different as possible from its surrounding colors to make the text “pop” off the sign. Because most successful sign colors are normally dark, white text usually works best. However, if you selected a lighter color, you’ll need to go with black text.

Type size and type face are also important considerations in designing a political campaign sign. Too often, I see signs with terrific background colors, excellent selection for text color, and then the text was too small, too skinny, or just too busy. Remember that most people are passing by in their cars and can’t divert their eyes from the road, so the sign will most likely stay in a person’s peripheral vision. To increase the chances of the sign being read, make the type as large as you can. Select a type face that is clean, has a medium stroke width, and allows adequate spacing between letters. The best type faces for this purpose are known as sans serifs (meaning they lack the decorative details of other type faces like Times New Roman).

Recognition vs. Recall — Once you read it, you have to be able to remember it. The third goal of the sign is to make a person remember the name of the candidate.

Let’s say I show you an object and then hide it from you. Which task do you think will be easier: picking the object out from a photo of several objects, or describing the object to me from memory? Most people find that picking the object out of the photo is easier. This demonstrates a principle of human memory that says humans are much better at recognizing something than they are at recalling something.

How does this apply to political campaign signs? Well, when voters are at the polls, they have a list of candidates to choose from, much like our example of selecting the object from the photo. Therefore, the most prominent item on the political sign needs to reinforce in a voter’s memory the content of that list. In 99.9% of cases, this means a candidate’s last name better be the largest item on the sign.

The principals of Human Factors can apply to everything that we design, whether it’s a complex system or a simple political campaign sign. Think about this – last election season I had to laugh at a sign posted all around my town. The most prominent element on this candidate’s sign was her photo. She might as well have thrown all those signs in the trash, because nowhere on a ballot are there photos of candidates. If someone wanted to vote for her, they would have had to figure out which candidate on the ballot had shoulder-length brown hair and glasses.

Elizabeth Mauer received her Masters in Human-Computer Interaction and a BS in Cognitive Science from Carnegie Mellon University. Based in Cary, she is a Human Factors Specialist for HumanCentric (, with a focus on user research, usability and user interface design. Elizabeth is an active member of the Human Factors and Ergonomics Society. She can be reached at