Usability Dynamics, the analysis and implementation of product usability characteristics, is based upon 5 Profound Principles:
1.DUALITY: Every product has a double nature. It performs two services: one for the customer and another for the company. The product must satisfy the needs of the customer, and communicate a specific idea about, or reinforce the established reputation of, the company that provides the product.
The product acts as a “sales person” for the company by the way it solves the customer's problem, or enhances the customer's life. More selling is accomplished by a good product on its own behalf than the combined efforts of entire sales forces.
Conversely, more buyer's remorse and customer returns are generated by a faulty product to its own detriment than the combined forces of all its competitors. The customer expects a product to perform a task for him or her, while the company expects that same product to also accomplish a purpose for the company.
This two-fold function of a product, incorporated in the Five Mandatory Modes (see post on this topic), is rarely addressed by current usability research.
2.INVISIBILITY: This is a somewhat uncanny, disturbing quality of usability. It's extraordinarily important to understand that usability is not seen immediately or directly in the product itself, nor in its sales presentation, nor in the official viewpoint of the company. Products don't read mission statements or vision declarations. Nor are they necessarily the embodiments of the corporate culture.
Product usability is initially, prior to analysis, an absolutely unknown factor. It is revealed only by non-invasively observing the interaction between a product and a representative user.
Focus groups, questionnaires, surveys, and other subjective reports typically yield accomodative (telling you what they think you want to hear), non-incidental (derived from unreliable memories of past, non-immediate usage of the product) data.
Such artificial scenarios as Think Aloud User Testing (most users don't talk to themselves when operating a product), Cooperative Interaction Surveillance (most users don't have a companion helping them operate a product), Guideline Adherence Diagnostics (guidelines may be biased and irrelevant to a particular product), and Cognitive Walkthroughs (the product designer posing as a representative user is far-fetched at best, and task selections are not typical) are also of comparatively limited value.
All these academically prized methods of evaluation fall woefully short of the analytical results obtainable from trained personnel engaged in silent, non-participatory, unintrusive customer observation.
Pure, unbiased usability data can be generated only by watching what the customer does with the product, with no prompting, explanation, or assistance from anyone.
If this kind of investigation cannot be performed, Heuristic Expert Evaluations (reviews of a product by a usability specialist, in accordance with scientifically derived guidelines) come closest to pure analysis, when based on accumulated observations of single users independently interacting with similar or nearly identical products.
The safest assumption is that the customer will attempt to use a product in a condition of solitude, whether at work or at home. In addition, the average user can usually be regarded as having average skills, an attitude of impatience, a low tolerance for frustration, a distracting environment, a feeling of discomfort (especially if at the computer for hours), and a strong desire to operate the product intuitively.
While other people may in fact be in the vicinity of the user, work associates for example, they cannot be relied upon to take the time to help, or assumed to have the ability to help. Furthermore, and this should be obvious, they are not an intrinsic part of the product.
It's surprising how difficult it is to get supposed “usability experts” and a company's product designers to understand this basic fact of sound analysis procedures. External influences in usability testing situations are generally divorced from customer reality, and serve only to contaminate the usability tests, rendering them largely worthless.
3.UNIVERSALITY: Usability is desired by all customers, and should, whenever possible, accommodate all levels of interest, need, and skill.
Early adopters, those who want shocking new technologies and wildly innovative services, are typically more tolerant of inherent complexity, task performance difficulty, and “good enough” usability. They pride themselves in being so competent they can master what others would reject in bewildered frustration.
This is why some products are released in an imperfect, problematic version. Highly experienced users don't mind, and may even enjoy, grappling with a new device or learning a new technique, as long as they eventually accomplish something that makes the struggle worth it, something that will impress their peers.
However, in many cases, it's a good idea to design a product for maximum usability across all ranges of expertise, from lowest to highest.
Those who are satisfied with easy implementation and fast results will be happy with the product's basic simplicity, yet look forward to opportunity to develop new skills to take advantage of advanced complexities that are available.
Those who demand advanced features and more rigorous applications will appreciate the speed with which they can start completing tasks, yet not feel the entire product has been "dumbed down" by having only beginner's features.
In some cases, it may not be feasible to embody this ideal of universal usability in a single product. One version of the product may have to be offered to neophytes, with a different version offered to seasoned pros.
4.INFINITY: The improvement of a product's usability is virtually unlimited. Related services and add-on enhancements can escalate endlessly. Most modern products lend themselves to constant development and redesign, with seemingly endless proliferations of styles, attributes, and customer market segmentations.
The company that becomes smug, and refuses to recognize that products must keep pace with increasing customer sophistication and industry innovations, will be easy prey for a savvy competitor.
5.INSTABILITY: Usability is not a static quality. What seems easy to use today may seem pathetically primitive and aggravating a few years from now. A highly usable product may be defeated in the marketplace by another product that is even easier and more convenient.
New users enter the market with new expectations.
Veteran users search the product offerings of various providers, hoping to find new features and designs.
As customers and competing products evolve, the perceived usability of any given product may also change.
Thus, a product's usability is never a permanently established fact that can be glibly taken for granted.
Its usability should be evaluated on a periodic, ongoing basis.