The lack of structured, testable theories has also been a valid criticism of human factors, something I realized when siting in on a recent Human Factors 101 class as an observer. At several points it seemed as if the class thought the entire field was intuition rather than something learned through years of study (go figure). So I sketched a rough hierarchy of how I viewed design considerations (the UX side):
6 Subshells of Human-Centred Design
- Sensory Subshell (Aesthetic, Auditory, Olfactory, Tactile)
- Structural Subshell
- Linguistic Subshell
- Informational Subshell
- Psychological Subshell
- Social Subshell
The Hierarchy presents design considerations in three shells and six subshells, from their most basic to the most complex level.
The first shell is the Perception Shell. It focuses on the item itself and its “hard” qualities.
In the Perception Shell, the first subshell (Sensory) represents the appearance and sense qualities of the design: sight, sound, smell, taste, touch. This level represents only the description of the agent’s qualities; although it may imply the existence of a user (who obviously must be present for qualities like sight and smell to be meaningful), no explicit interaction is specified. In the web design sphere this would entail the visual treatment of the page and any music or sound effects played. In the industrial design sphere, this would include how the object affects all the senses.
The second subshell is Structural. This refers to the layout and spatial orientation of elements. In other words, this subshell identifies how elements related with each other, through space and function.
The Interactional Shell focuses on the relationship between the item and the (human) user.
The first subshell in this shell is Linguistic. This describes how people perceive the language and metaphor involved in the product. For websites this involves the copy and any metaphors employed (e.g. calendar widgets, book-like tabs, etc.). For consumer items this would involve any symbolic agents (text, graphics or other) employed, such as the control symbols for a game console controller.
The next subshell is Informational. This refers, most of all, to the information conveyed to the user. This includes both what is conveyed (e.g., the current radiation levels, stability and energy output of the nuclear reactor) and how it is conveyed (e.g., the conceptual organization of information elements into dials, gauges and other displays, and the user’s actual mental model of the system’s functions).
The Integration Shell focuses on the user and only treats the item as an entity that affects the user.
The Psychological Subshell focuses on how the user feels and behaves, in isolation, as a result of the interaction. This includes emotional reactions, psychological rules that come into play (e.g., the Media Equation or the Computers As a Social Agent (CASA) paradigm), and changes in expectations or prejudices in in dealing with future systems.
The Social Subshell extends the Psychological Subshell to multiple users in two distinct ways. First, it refers to how users behave with each other when using the same interface. For example, on the web people often interact through email, online games or chat programs where the design of such sites is specifically catered to these end-goals. In consumer products, cars have distinct social impacts on how the passengers interact with one another and adopt roles appropriate to the design of the car (e.g. driver, front-seat passenger and back-seat passenger, who can sometimes be a back seat driver!).
Second, it refers to how the interactions between users themselves in lieu of the interface is affected by some users’ previous experience with the interface. A perfect example is the technological meme: certain concepts and words (e.g., ‘n00b’, ‘lol’, ‘spam’) permeate through the general public and influence how people speak to each other and what issues they speak about, even when much of the audience has never experienced the interfaces first-hand. With the rise of viral media and social networking through technology, this area’s importance as a design consideration is at the forefront.
A few notes:
‘Interface’ is a pretty bad word to use, since it’s connotations are too much in the digital sphere (as opposed to the physical), but I couldn’t think of something better. Device and object are too physical. Technology may be better, as it could equally imply digital or physical thing.
The heirarchy is structured along 2 main variables: agent focus, and single vs. multiple. Shells are demarcated according to agent focus, i.e. Shell 1 (Perception) focuses on the interface, Shell 2 (Interaction) on user-interface interaction, and Shell 3 (Integration) on the users. Subshells are divided by single vs. multiple, i.e. focusing on one element versus relationships between elements, on the meaning of each element versus the meaning of the interface as a whole, and on a given user versus the relationship between multiple users.