This article examines how consistency in design benefits both the user’s perception of the design and the system’s usability. The convenience of consistency lies in the fact that its systems are’ . . . more usable and learnable when similar parts are expressed in similar ways’ (Lidwell, Holden & Butler, 2010, p. 46). Consequently, this method allows people to familiarize themselves with existing knowledge and enhance their understanding of new content which is expressed in a similar way. Four fundamental types of consistency are explained in greater detail. They include the aesthetic, functional, internal and external elements of design.
Firstly, aesthetic consistency is based on the product’s appearance, typography, colour and style, which enable identification and recognition. Achieving aesthetic consistency does not mean pleasing ourselves; rather it serves more as a dependent pattern of design that is understandable and recognisable to other users (Schlatter & Levinson, 2013, p. 3.). Simplicity and repetition of stylistic design applications for a particular service or product trigger’s a person’s memory and their affiliation towards the design. This way, people establish an effective interaction with the product which nevertheless meets their expectations.
Functional consistency serves to provide the user with existing knowledge that can improve their understanding of how new systems function. For example, the prevalent use of the play, rewind and replay symbols on a remote control can be seen on many other devices such as MP3 players or slide projectors (Lidwell, Holden & Butler, 2010, p. 46). As a result, these consistent symbols and buttons help navigate the user in the right direction giving them a simple and usable mechanism to follow.
Making a link between the aesthetics and the functionality of a system means establishing an internal relationship with the system’s design protocol. Internal consistency ‘means a consistency in the design itself’ (Lee, Lee, Moon & Park, 2013, p. 46). Insuring all elements in the system are cohesive and consistent fosters a positive experience for the user and their comprehension. External consistency on the other hand, strives to develop an interrelated consistency ‘across multiple, independent systems’ (Lidwell, Holden & Butler, 2012, p. 46). However, the design principles range from one system to another, creating a problematic task for effective usability and performance.
Lee, J., Lee, D., Moon, J., & Park, M. (2013). Factors affecting the perceived usability of the mobile web portal services: comparing simplicity with consistency. Information technology and management, 14(1), 43-57.
Lidwell, W., Holden, K., & Butler, J. (2003). Universal principles of design. Massachusetts, MA: Rockport.
Schlatter, T., & Levinson, D. (2013). Visual usability: Principles and practices for designing digital applications. Amsterdam, Netherlands: Elsevier Science.