“Consistency in design is about making elements uniform” (Spool, J. 2005)
Consistency is a factor in design or systems usability, when a design is used consistently it becomes something the viewer can recognise and use past experience to draw an understanding of the system. There are four types of consistency, functional, aesthetic, internal and external. (Lidwell, Holden, Butler, 2003).
Functional consistency is when certain symbols or codes are used on a range of different devices and over time becomes common knowledge for the users. For example, the symbol for a pause button, it is used on television remotes, gaming consoles, stereos and MP3 players. Generally when someone is trying to figure out how to pause something they look for the two vertical lines side by side.
Aesthetic consistency is referring to the consistency in the look of something. Certain brands will use the same style of something to give make it recognizable. The brand Louis Vuitton, a bag or fashion item from the brand can be associated to coming from that brand almost instantly. Consumers also will be more likely to trust a company brand they recognize, “consistency creates impressions of one well-managed image” (Schmitt., Simonson. 1997).
When elements are repeated throughout a design this is called internal consistency. A way to tell the difference between internal and external is that external consistency is “the degree to which a product is consistent with some reference other than a part of itself” (Zuschlag, M. 2010) and internal consistency is the degree in which a product is consistent within itself. (Zuschlag, M. 2010)
Lidwell, W., Holden, K., & Butler, J. (2003). Aesthetic-Usability Effect. In Universal Principle of Design (pp. 46). Massachusetts: Rockport.
Schmitt, B., Simonson, A. (1997) Marketing aesthetics: the strategic management of brands, identity, and image New York: Free Press
Zuschlag, M. (2010). Achieving and Balancing Consistency in User Interface Design. Retrieved from http://www.uxmatters.com/mt/archives/2010/07/achieving-and-balancing-consistency-in-user-interface-design.php