Stop signs are always red. Exit signs are green. Play buttons are triangles. These are patterns and norms that, when appropriately leveraged in a design, can help communicate expectations and function. It doesn’t matter if you are an interface designer working on a software UI, a software engineer writing code or a manger preparing a powerpoint presentation: consistency is important.

What consistency is not, however, is copy + paste. As a great designer on the maps.nokia.com team said in a design review recently: “Consistency is not a rubber stamp.” It’s not a cookie cutter. It is a careful and thoughtful association between what you are doing and the user’s current knowledge. In other words, the question to ask is: “will this design allow my user understand what they need to do or what I am trying to communicate to them, given their experience, knowledge and understanding?” Two elements of a system can be consistent with each other without being the same.

Consistency for consistency’s sake (or, on other words, forcing total consistency at the expense of function) is a design crime of an similar magnitude.

Rather than asking the question: “is this consistent?” – ask the question: “will my user/reader/audience/etc easily understand, given their context and knowledge?”

As Emerson famously pointed out:

“A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines. With consistency a great soul has simply nothing to do.”