This blog post is the second in a series of two about Human Computer Interaction (HCI)
Principles of User Interface Design for HCI systems
Since I am looking at HCI relative to interface design, it is important to underline how to improve the quality of user interface designs. Thus, as interface designer one should be mindful of the principles of user interface design. According to Larry Constantine and Lucy Lockwood, these are:
1. The structure principle – This is concerned with the overall user interface architecture and layout. An interface design should be organized in a way that is clear, apparent and intuitive to users. In other words similar things should somewhat resemble each other. For example, toolbar buttons should all look like toolbar buttons.
2. The simplicity principle – The interface design should make simple, common tasks easy, communicating clearly and simply in the user’s own language. For example a search bar with the word ‘Search’ is usually better than the convoluted ‘Quick Keyword Search’.
3. The visibility principle – All the options and tools needed to accomplish given tasks should be visible and easily accessible on the interface design without distracting the user with redundant information.
4. The feedback principle – A good interface design should keep users informed of actions or interpretations, changes of condition or errors that are relevant through clear and concise language. This helps users feel in control of the process by being aware of their actions.
5. The tolerance principle – The interface design should be able to accommodate a certain amount of failure from users (users, just like interface designers, are not infallible). A wrong click or some such other should be rectifiable. Undo and redo features that allow users to effectively time-travel through their steps are a good example of this principle.
6. The reuse principle – An interface design should reuse internal and external components and behaviors, maintaining consistency with purpose rather than merely arbitrary consistency, thus reducing the need for users to rethink and remember. This is also referred to as the memorability of an interface design.
How to ensure that User Interface Design principles lead to optimal HCI systems
To ensure that these principles guide the interface design process and lead to optimal HCI systems, the use of wireframe tools can be useful. Often, the large number of stakeholders with various levels of technical expertise in the design process requires the use of such tools for visualizing requirements and concepts. Tools suitable for wireframing, such as Pidoco, a cloud-based rapid prototyping tool that works through a browser, allows interface designers to create wireframe prototypes of graphical user interfaces with simple drag and drop handling without the need for any programming. Interface designers can use this system to collaborate within a team through the cloud and get feedback from sharing prototypes, even going as far as conducting remote usability testing. This type of approach makes optimizing human computer interaction much simpler and safer and leads to more reliable results.