No single user is “special” – or maybe all users are? Either way you look at it, we as interaction designers will encounter contexts of use or knowledge domains out of the ordinary at some point or other during our career. In my experience, designers need not apply magic tools when designing for special situations. It is however beneficial to bear in mind some core differences between specialized use contexts and the mainstream use of a mass consumer product such as a social networking site or a mobile phone. And that’s what I want to focus on in this article.

In the digital work environment of a specialist such as the nurse, designing the patient vital sign monitor requires the interaction designer to use and apply domain-specific knowledge. “Systolic Blood Pressure” is not just a label in a list; you have to know what it means. And then you have to design what it means to the nurse.

So how can we design the best possible systems when faced with these special contexts? How do we ensure that interactive systems for specialized users do not become needlessly complex and difficult to use? This article provides an introduction to domain of specialized interaction design, and provides you with some key guidelines for a successful UX result.

Designing for a particular context

Think of a work arena or professional domain with highly trained users.

• What systems surround the user?
• Are the systems interactive in nature?
• What specific tasks will require a high degree of knowledge when performed?

Any interactive device can be the subject of a “specialized” use context.In the definition used here, the specialized interaction design comes into relevance when a user is subjected to prolonged or intensive periods of use on a particular system. And this is typically as part of a professional workspace. This context requires a highly trained user for operation. It can be the transaction platform of a financial instrument trader, the word processor of a writer, the table of a DJ, the decision-making tool of a surgeon or the steering wheel of a Formula-1 racer.

What makes your user special?

More and more domains of highly trained and demanding users become the subject of interaction design. Many specialized work domains were previously supported by fitting mass-produced systems to do the job; it has however become more commonplace to see interactive solutions targeted for particular contexts.

A special body of knowledge

The training or education of the specialized users is an important factor for consideration. The body of knowledge that can be presupposed for these users gives the designer many advantages in designing an efficient use of the system. To name a few:

• Specific domain symbology standards can contain important data or information, that otherwise would need extensive labeling and explanation;
• Abbreviation or shortening words can make a lot of sense to trained users. This allows for more effective real estate distribution; such as referring directly to procedure numbers or shortname references – the user will know the reference through repeated training;
• Features need not be that transparent – hidden shortcuts and interactive sequences can more easily be learned to support super-usage;
• Guidance and supportive features can be kept to a minimum. This doesn’t mean the system doesn’t have to be learnable.

Use of specialized symbology. Incomprehensible to outsiders but extremely effective to the domain user. Example shows APP6A; infantry, recon and anti-armour symbols.

The body of knowledge that supports the design process can also challenge it. No interaction designer can ever completely understand the work context of a surgeon or a pilot. A system that needs to be easily accesible to a user with multiple years of pre-training or education, interaction designers cannot target in early iterations without support. In addition, the world of the user can be hard to replicate or even physically see or visit.

For this purpose, it is very common to employ in-house domain experts. These domain advisors are not a part of the client product ownership but work closely with the UX and development teams. They are an indispensable part of designing the right solution for the end user.

Trained users and steep learning curves

A core difference when designing systems for special users is how the user accesses the learning curve of the system. A specialized interaction design can often suppose the end user to enter the interactive system relatively high on its learning curve through pre-training or guidance.

This fact allows the designer to avoid supportive low-barrier entry features that similar systems would require when designed for a broader field of users. The reduction in functional redundancy, that might make sense for exploratory use, appears as noise and friction to the trained user. The very design choice that makes an interactive system seem inaccessible to the untrained eye might be what actually makes it highly usable for prolonged use.

This can be seen when designing the overall navigation structure of a specialized system. An effective design will remove most layers of navigation by avoiding steps, wizard-like interaction patterns, states and modes. Multiple systems can be placed side-by-side with positive result. This is why financial traders love multiple displays. Effective design occurs when striving to populate the first layer of navigation as much as possible.

Challenging procedure

Users within a specialized domain will often have developed a rigid doctrine or detailed procedures facilitating task completion. This can be both a help and a burden to the interaction designer. On one hand, a process can serve as a guideline for developing an efficient system since these procedures have been sharpened over years by multiple groups of users to yield maximum output. Best practices are common. For instance, a work hazard checklist can serve as an important tool when digitizing the workflow.

Populating the outermost layer of navigation entirely.

However, the same tool can hinder improvement to the everyday life of the user. In the case of a specific physical checklist, users can be highly resistant to change. Maybe less steps in the operation are needed with a digital device. Maybe they steps can be overlapped or re-ordered with a new interaction pattern. The digital tool might also automate some features. But this doesn’t matter – users have invested time and energy and the current procedure has become a natural and reflex-like part of work.

As an interaction designer, it then becomes essential to challenge the “way we do it” and reach the point of minimum justification for change.

Designing for attention span

Monitor for patient vital signs - focused and very short periods of use.

Considering the attention span of the highly trained user is one of the key contributors to a successful design, and this design approach is not even specific to specialized users. The user directs varying amounts of attention towards any system we design. But for highly trained users, the difference can be more pronounced.

In the case of a system for analysis, such as the vital sign monitor, the specialist has a very low percentage of total work time dedicated to that system. Maybe the user just briefly turns to the display for look-up or analysis, then returns to the main task. The system becomes a supportive system for critical decisionmaking surrounding a different main task. For this, the interaction design must ensure easy access, very low friction and mostly no layers of navigation. Systems for monitoring can use sound effectively (but should be used scarcely) to direct attention.

The air traffic controller workspace - a place of prolonged and intensive use.

Other systems require prolonged periods with 100% of user attention directed towards the system, such as is the case with the air traffic controller workspace. In this case, the design of the screen must apply methods for noise- and stressfree visuals, but it can also be highly effective in the use of real estate. When anyone sits long hours looking at the same screen, small pixel changes are sufficient to indicate change or needed reaction. Combined with specialized symbology, content can be presented in surprisingly compact ways and still make a world of sense.