Jakob’s Law is a principle conceptualised by Jakob Nielson, a pioneering human design researcher and co-founder of the Nielson Norman Group (an American computer user interface and user experience consulting firm). The principle proposes that users spend most of their time on other sites and would therefore prefer your site to work the same way as all the other sites already know. Users will transfer expectations they have built around one familiar product to another that appears.
Jakob’s Law is underpinned by the psychological concept of a user mental model. A mental model refers to what the user believes about a system before using. These beliefs are developed from previous experiences and opinions developed from using existing products. By leveraging existing mental models, UX designers can create superior user experiences in which the individual can focus on their tasks rather on learning new models. For example, design software like Figma and Adobe utilises similar graphical user interface elements like icons and layouts. This reduces the time and effort designers spend learning new programs, enhancing customer satisfaction with these products and boosting revenue for manufacturers.
(Above) Examples of Kare’s simple, fun iconography used to enhance Apple customers experience navigating the original Apple Macintosh
Susan Kare’s pioneering work in collaboration with Apple is a great example of a designer thoughtfully considering the user’s mental model to create a user friendly experience. With a background in graphic design, Kare was recruited by Apple in 1982 to design the Apple Macintosh GUI. At this time, computers were very difficult for non-experts to approach and navigate, creating a sense of coldness that deterred potential customers. Under Kare’s direction, Apple successfully humanised computer design through a design technique known as Skeuomorphism. This term is used to describe the design of graphic objects which mimic their real-world objects in how they appear or are used. This is an incredibly successful concept which was used by Kare to create clever and simple icons like the dog-eared page to indicate the user’s ability to open a document.
(above) Examples of original Macintosh UI
Many of Kare’s designs can be considered really playful and child-like as well as simple and understandable. For example, the “Happy Mac” smiling computer icon which employs the familiarity of a cartoon smiley face, greets the user with immediate positive and welcoming connotations and encourages us to continue using the product. These designs follow Kare’s belief in the principle that all interface designs should be familiar for use. The sustainability and durability of Kare’s designs is also very interesting to note, with many icons remaining a staple on popular programs like Microsoft and Adobe.