“A foolish consistency is the hobgoblin of little minds.” – Ralph Waldo Emerson, (1841)
Referring to the ability of a system to be easier to use and learn, when parts which are similar are also used similarly. In doing this, users are able to apply what they have learned to other contexts quickly.
THE FOUR TYPES OF CONSISTENCY
Referring to the style and appearance of a design using colour, font and graphic. This allows people to recognize designs such as company logos and form a particular emotion or thought about a brand.
Take Mercedes Benz for example:
Figure 1. Consistency Principle Example. (Source: Mercedes Benz, 2015)
The logo is consistent in that is is featured on each and every vehicle the company creates which helps to maintain it’s prestige association in the motor industry. The logo has remained the same since production began and is in clear view of any person passing a Mercedes on the road embedding the image into people’s minds without even realizing it.
Helping to improve usability and learnability, Functional Consistency refers to the consistent meaning and action of a design. Take a traffic light for example:
Firgure 2. Consistency Principle Example. (Source: Wow! Japan, 2015)
Green always means go, Yellow always means slow down and Red always means stop. This allows users to grasp prior understanding and to pass it on to new devices. For example, a more modern device such as an ipod uses the same system.
Figure 3. Consistency Principle Example. (Source: Bugmenot, 2015)
The “pause”, “Stop”, “Play”, “Forward” and “Back” buttons are universal in their meaning and will never change which makes the product super easy to interpret no matter what the device is used for. This creates consistency in our understanding of what these buttons mean on a product.
Referring to consistency with other elements within a system. Internal Consistency pursues a trust within the user due to the appearance that a product has been well thought about in it’s design process. Both Aesthetically and Functionally with existing elements within its group.
“Consistent representation of these objects means the user recognizes them for what they are when encountered..Without consistent representation, a user will struggle to understand what they are looking at.” (Cole, 2012)
Park Signs for example:
Figure 4. Consistency Principle Example. (Source: Ebisu Park, 2015)
A person within the park is well aware that a sign belonging to this group means that it is placed by the park to inform them of something. If the sign was of a different design, the patron may not be aware that the sign is even related to the park itself and may not pay any attention. Each of these signs are designed logically and consistently.
Firgure 5. Consistency Principle Example. (Source: JP Fire Protection Systems, 2015)
Notice that most of the above emergency alarms are colored red. This is an intentional consistency to trigger a user to understand that the alarm is in place.
“External consistency refers to consistency with other elements in a system” (Lidwell, Holden & Butler, 2003)
Similar to the internal consistency yet spread among multiple, independent systems. This is not as easy to achieve because different design standards are harder to perceive among customary design standards.
“Without consistent representation, a user will struggle to understand what they are looking at.” (Cole, 2012)
It is important that we remain consistent within a design to ensure that a user develops the same representation each time. If we do not, this can confuse the user and leave them unsure as to what the product is trying to demonstrate.
When considering consistency, it is important to not just think visually but also about the interactions and behavior patterns that exist within your designs. We must consider how the user will interact with our product, how animations and different items may react to the users input. When changing these patterns drastically from page to page, we are more likely to confuse the user.
Cole, D. (2012). “Why is Consistency important in Design?”. Retrieved October 30th, 2015, from https://www.quora.com/Why-is-consistency-important-in-design.
Hertz, R. (1948). Chance and symbol: a study in aesthetic and ethical consistency, Univ. of Chicago Press.
Lidwell, W., Holden, K., Butler, J. (2003). Aesthetic-Usability Effect. In Universal Principles of Design (pp. 46). Massachusetts: Rockport.
Shillcock, R. (2013). “Building Consistency and Relationships into Your Designs.” Retrieved October 29, 2015, from http://webdesign.tutsplus.com/articles/building-consistency-and-relationships-into-your-designs–webdesign-14849.)