Models and Theories in Human-Computer Interaction/The Importance of Norman's Design Principles

In the first chapter “The Psychopathology of Everyday Things”, Norman elaborates on the 6 important principles of design including affordance, signifier, constraints, mapping, feedback (together making up discoverability principle) and conceptual model. As an interface designer, these six principles set up a consistent foundation for my design strategy across different products that I work on. I’d like to use the following examples that I found from my daily design tasks to reiterate the importance of these principles.

Affordance: Scrolling has been a very common practice for web pages. Just a small touch of covering the elements in the bottom of page provides a strong affordance to user that there is more content below and therefore it prompts user to scroll.

Signifier: As scrolling a page can be long and time-consuming task (infinite scrolling), having a small signifier like “Back to top” icon or button in the bottom of the page provides a quick way for user to move back up.

Constraints: Creating a UI kit provides good constraint for the design process of a product. It helps to avoid introducing new elements every time a new page/feature gets designed.

Mapping: In crowded interfaces such as a landing page or a dashboard, grouping together the elements that share a common theme/content/visual traits and arranging them in the hierarchy of importance provides a good natural mapping for users to digest through the information.

Feedback: The use of simple animation recently has been used more often in mobile applications as it provides instant feedback on every step user goes through to accomplish a task.

Conceptual model: As much as designers want to keep the design clean and simplified, having obvious spelled-out text for important tasks (versus using highly abstract icons) provides users immediate understanding of they are supposed to do.