Understanding the End User

The design and usability techniques described in the previous sections are a standard for good interaction and interface design. It is also important to consider the location and goals of end users as well as the location and position of the actual touch panel. Vertical wall mounted panels will function differently than horizontal panels and tabletop or handheld panels will have different needs all together.

The initial work on a design can be the most critical. During this phase, you decide the general shape of your interface. If the foundation work is flawed, it is difficult to correct later. This part of the process involves not only defining your interface’s objectives and features, but understanding who your users are and their tasks, intentions, and goals. For example, a

residential touch panel will have very different users and requirements than an auditorium or conference room. Designing for your users involves understanding the following factors:

• Background — age, gender, expertise, experience level, physical limitations and special needs.
• Work environment — equipment, social and cultural influences, and physical surroundings.
• Current task organization — steps required, dependencies, redundant activities and output objective.

Begin defining the conceptual framework to represent your interface with the knowledge and experience of your target audience. Consider the basic organization and different types of metaphors that can be used. Observing users at their current tasks can provide ideas about effective metaphors. To develop for the widest audience, design for the most common user. Consider the following examples:

• Beginning users often have difficulty using a touch screen. For example, multi-touch gestures are skills that may take time for new users to remember.
• Navigation on a touch panel can be difficult because it requires remembering the hierarchy and path they have traveled, which differs from a website with a crumb trail.
• Sliding a finger is different from a tap selection, so many beginning users have difficulty distinguishing these two actions, or they overdo it.
• Beginning users often have difficulty with window management. They do not always realize that overlapping windows represent a three-dimensional space. As a result, when a window hides another, a user may assume it no longer exists.
• Advanced users want efficiency. The challenge in designing for advanced users is providing efficiency without introducing complexity for less-experienced users. In addition, advanced users may be dependent upon particular interfaces, making it difficult for them to adapt to significant rearrangement of or changes in an interface.

Document your design. Writing down your design plan not only provides a valuable reference and form of communication, but often helps make the design more concrete and reveals issues and gaps. If you are in doubt about the appropriate look and feel for a function or tool, look to the template as a reference for conventions.