Off to a good startTen steps towards a better interface
Artemis Giagkoy, deputy director of the postgraduate course in MA Design at AKTO, published in 2002 an influential article with the title «Shaping technology for everyday use: The case of radio set design». As described by the author the article “examines the design of the radio device, which is regarded as an important historical example of user interface design” (Giagkoy, 2002).
After reading this article, I’d like to set out in brief, the basic principles of interface design, with the hope that they will be the subject of a fruitful reflection.
Visibility
The rule: All components of the interface (User Interface) must be visible to the user.
Visible, recognizable, is for example, the button «PLAY» on A/V devices or audio and video applications. It is necessary to know if specific typefaces, images and shapes exist that represent certain concepts – that is to look for symbols. Remember that the three basic modes of expression used by graphic design as tools of the visual language are: Representation, Symbolism, subtraction.
Feedback
The rule: All components of the interface (User Interface) must return enough information in response to user actions.
When an action is successful, a program informs the user about the successful completion with a text and/or a sound alert like, for instance, the Microsoft Windows exclamation default sound. In case of incorrect input or a system error, it is important that the system returns the necessary information and directs the user to the actions necessary to a successful completion of the task.
Affordance
The rule: All components of the interface (User Interface) must indicate their potential use.
This is my favorite rule because I belong to a certain group of people who are not sure whether to pull or push the door at the entrance to a door, if the characteristic indication «Pull / Push» is not visible on the glass.
Don Norman introduced the idea of “availability” in design back in 1988: “To afford means to give a clue. The clue is of how to interact ” (Affordances and Design, 2004).
To a subsequent publication, he adds the idea of distinct availability, otherwise “perceived affordance”: “(…) in design, we care much more about what the user perceives than what is actually true.” The distinct availability, namely what the user regards as “evident use” is a point of concern for most designers. The handle of a door prompts the user to pull. The designer will not be content with that. He will take into consideration the need of the user to recognize the use of the door handle by the indication «Pull / Push».
“Things and objects of the natural world pose potential uses of the same things, and represent an individual’s activity» (Gibson, 2002).
At this point, it should be noted that the principle of availability comes from the theory of direct perception (or “ecological theory”) of psychologist James J. Gibson (James J. Gibson and the Psychology of perception, 2007). This theory deals with two basic principles: stable relations of characteristics of objects and the principle of availability. First, it points out the characteristic of the causal relationship between objects: The arrangement and relationships of the individual components of an object in its natural environment cause direct perception without the need for higher cognitive functions. The result is the relevance of all data and their presentation in a way that confirms the direct relationship.
Consistency
The rule: All components of the interface (User Interface) must be organized according to a logical sequence.
Most of the applications that we frequently use in our computer are characterized by uniformity in their general characteristics. For example, in a dialog box, we usually expect to find two buttons (Cancel and OK). The buttons have the same style as the dialogue box. In Windows applications, we find the symbol [x] in the upper right corner of the dialog box. The same symbol is used in all dialog boxes of the operating system and performs the same functions.
Consistency is based on learnability, which is the basis of the theory of learner-centered design. The aim is to develop an understanding of the user – the activation of the human system of “constructing knowledge”. From observation we learn that users easily understand and recognize the use of interface elements when they maintain symmetrical shape and structural visualization (default look and feel).
Simplicity
The rule: Make the user tasks easy and simple in execution.
Don Norman urges: “Follow conventional usage, both in the choice of images and the allowable interactions” (Affordances and Design, 2004). Simplicity is the use of items (buttons, menus, toolbars), which the user is already accustomed to, so that he will not have to spend time to learn what they do and how they operate. The purpose here is to minimize the user’s actions towards the completion of a task.
Structure
The rule: Put together the elements of the interface (User Interface) so that the result is meaningful to the user
The arrangement of the elements that compose the interface is important. The user’s expectation is that the distribution of elements in the layout will be based on the relationship between them. Thus, all the buttons and options related to a specific action should reside in the same space.
Tolerance
The rule: The user interface must be designed in a way that prevents user’s mistakes and helps him/her follow the steps necessary for the successful completion of a task.
Tolerance refers to the potential behavior of the user. Every user action is a chance for another mistake. Mistakes are not always due to bad design. Because of the absence of the necessary cognitive skills, lack of familiarity with technology or external factors, the user can act in an unpredictable way and his actions may lead to a program error.
The designer gets prepared for such error cases, using messages or other forms of feedback that inform the user about his/her actions and make suggestions about the ways to avoid possible errors. Experimentation and mistakes enhance learnability if there has been adequate planning for useful feedback.
List of references:
Giagkoy, A. (2002), “Shaping technology for everyday use: The case of radio set design”, The Design Journal, 1(5), p.2-13.
Affordances and Design (2004). Available at: http://www.jnd.org/dn.mss/affordances_and.html (Accessed: 22 November 2010)
James J. Gibson and the Psychology of perception (2007) Available at: http://www.ideal.forestry.ubc.ca/frst524/05_gibson.pdf (Accessed: 22 November 2010)
Link to sliderocket presentation
UI Design Principles – Towards a better user experience for cismic.co.uk by Zoe Marmara is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at docs.google.com.
