I was sitting with one of my youngest sons the other day to help him learn how to tell time. His workbook displayed an analog clock with the hour hand pointing to the 3 and the minute hand between the 1 and 2.
“What time does the clock show?” I asked.
He looked up at me and replied, “I don’t know.”
I thought, “Of course you do! You’re just not trying hard enough. Everybody knows that clock reads 3:07.”
Only, he didn’t know that. And as I attempted to explain how to read a clock I began to question how I had ever learned. There’s some logic to reading an analog clock but, honestly, a lot of it is simply memorizing a system. There’s no intuitiveness to reading a clock.
Put yourself in my son’s position for a minute. If you never saw a clock before but were asked to decipher how it indicates the time of day where would you start?
There are several elements present in this device that indicate the time of day:
60 hash marks (12 thick ones and 48 thin ones)
Three sticks affixed to a central point and moving at different speeds
The spaces between the numbers and the hash marks
All of these elements live in a circular field with a border around its circumference
To properly interpret the information presented in a visual system you have to understand what each element represents, the hierarchy of information presented, and how these elements relate to one another.
In the same way my son couldn't intuit how to read an analog clock don't assume the users of your visual system understand how it works either. This applies to websites, mobile apps, building signage, or subway maps.
There are many excellent resources for user interface and user experience best practices and it's not the purpose of this post to provide a comprehensive list. I simply want to emphasize that it's easy to forget about the intended user of your system and make assumptions based on your own experiences and knowledge. All designers have bias when it comes to creating a visual system for others to use, that's why it's important to have a second (or more) set of eyes look over what you've created. Conducting user tests with non-designers who are unfamiliar with your system is a good way to reveal unclear or confusing elements.