4.4 The Interface Is the Application

4.4.1 Design Approaches

Interface design has different approaches, which we will summarize here shortly. Some of the more interesting approaches will be discussed in more detail later in this section. To make a design successful, it is necessary to get the graphic design basics right. This means that the design language, the typography, use of colors, spatial organization, and temporal sequencing need to be defined and selected according to the task that needs to be implemented. In an increasingly globalized world, the challenges for design in overcoming cultural, social, and political barriers are immense.

To make design successful, it needs to be done with the human in mind. This human-centered approach to design applies not just to products or graphics, but includes the design of entire systems of things that people use and expect to function in a certain waysoftware interfaces, public transit systems, museum exhibits, work environments. It goes beyond the physical human factors (ergonomics) traditionally studied by designers, and considers the cognitive, social, cultural, and emotional factors that comprise users' needs.

Human-centered design is a product development process that involves people during all phases of development and is led by a multidisciplinary , collaborative team working toward a common goal: the creation of a useful, usable, and engaging user experience. The process focuses on the physical, cognitive, and social abilities of humans to facilitate understanding and ease of use in interactions between people and their environments.

To make design successful, it is not good enough to work with a specialist in one single area anymore. Working in interdisciplinary teams is a must, as many products often contain different types of technologies and processes, so design teams must include people who know the technologies and business processes in detail. It is often also very helpful to adapt ethnographic methods from the social sciences, such as direct, video, and still-camera observation, which allows for gathering information about users of the new design. Besides observation, social sciences often use contextual inquiry, interviews, focus groups, and market audits and reviews to find out if a certain design attracts the user group .

The contextual inquiry studies the context of work tasks in combination with the direct observation, making sure that the design fits into the overall picture and improves the performance of everything. Interviews are used to supplement contextual inquiry. Interviews are typically fast and informal and provide quick feedback. Focus groups in design are similar to marketing focus groups but with the intention of finding out how people do things. Market audits and reviews can help to identify larger trends and patterns and tend to be quantitative and homogeneous. All these techniques help to make design better even before starting.

Table 4.2. Human Factors in Design

There are four basic human factors that should influence the design of everything:

  • Physical How do people physically interact with things?

  • Cognitive How do people process and interpret information?

  • Social How do people behave in groups?

  • Cultural How do culturally based assumptions and preferences affect people's behaviors?

These guidelines help to solve complex problems by designing holistic systems of products and services that accommodate the user right from the beginning. This also means that it is necessary to advance the role of a designer from that of an implementor, who is carrying out someone else's orders, to that of a key business strategist capable of designing products and services that create entirely new markets.

There are four basic human factors that influence design: physical, cognitive, social, and cultural factors (see Table 4.2). These factors show the designer how people physically interact with things, how they process and interpret information, how they behave in groups, and how culturally based assumptions and preferences affect people's behaviors. Many designers do not take these factors into account and fail. But design in a me-centric world needs to adhere to these principles in order to be successful.

4.4.2 Task-Centered Design

Task-centered design is an approach where the design process is structured around specific tasks that the user wants to accomplish with the system being developed. These tasks are chosen early in the design effort, and then used to raise issues about the design, to aid in making design decisions, and to evaluate the design as it is developed.

This design approach combines a description of both people and their tasks to identify patterns of use so that appropriate content structures and relationships can be created. These relationships can then be put into context, relevance, and coherence. Context creates relationships to things people already understand, relevance shows how close the structure is to what people expect, and coherence makes sure all parts of the experience hang together as a whole. Task-centered design helps to create a taxonomy, rather than a hierarchy, because a hierarchy implies no overlap in the things we want and do.

This approach requires that designers find out which users will use the system and what they are going to do with it. As most systems are complex, it is important to choose some representative tasks first that will make sure that the whole design process is well defined. Once these tasks have been defined, one should try to find existing interfaces, learn from them, improve them, or create totally new interfaces, if the current ones available are bad. Once the interface design has been developed, a prototype should be built and tested by the user group. This prototype building should be iterated a few times, based on the feedback of the users, before it goes into production. One important thing to remember is that after the go-live date, the system needs to be monitored and changed, again based on the users' feedback.

But designers ought not be limited in their thinking to tasks that people do now. For example, a one-click purchase of books on Amazon.com [10] was a milestone, a revolution, and could be seen as a really inventive new task to achieve a human purpose not previously approachable in that way.

[10] http://www.amazon.com/

4.4.3 Human-Centered Task Analysis

Task analysis can be defined as the study of what a person is required to do, in terms of actions and/or cognitive processes, to achieve a task objective. The idea is that task analysis provides some structure for the description of tasks or activities, which then makes it easier to describe how activities fit together, and to explore what the implications of this may be for the design of products. But beyond simply "doing what's needed," a successful system has to merge smoothly into the user's existing world and work. This can be particularly useful when considering the design of interfaces of products and how users interact with them. The following is a very simple introduction to some of the concepts of task analysis, and is illustrated by a design example.

  • It is a discrete, step-by-step analysis of how people do things.

  • It identifies the goals of the target groupwhat they are trying to achieve.

  • It tries to identify typical patterns of use, sense of purpose, and sequence, and identifies problem areas.

Task analysis can be applied to studying how users use existing products, and such an analysis will assist in the process of understanding the difficulties they face in using existing products and improvements that might be needed. Task analysis techniques can also be used in a predictive fashion to represent how users may operate products that are being developed. Such representations can act as a vehicle for communication between developers and others involved in the development process, e.g., end-users or their representatives.

Task analysis techniques can also assist in the development of training manuals for products, as the structure that is implicit within the design of an interface is more easily revealed when represented in such a way. Task analysis techniques can also be used in the development of evaluation plans, as an understanding of what activities are the most important to the user or have critical consequences for their safety helps place priorities on any evaluation studies planned. Information on how often different activities need to be performed is also particularly useful for these purposes.

When doing an analysis, it is important to make sure that information is in the order that the user is likely to receive it. The design should make it easy to correct data that's often entered incorrectly, and the required hardware should fit in the space that users have available and look like it belongs there. These and a multitude of other interface considerations are often lost in traditional requirements analysis, but they can be uncovered when the designer takes time to look into the details of tasks that users actually perform.

Two processes are usually followed when a task analysis is conducted . The first is some analysis of sequence or dependency between different activities. Thus, it is important to understand a particular activity in the wider context. For example, a person using a communication aid may want to communicate hunger, but first needs to draw the attention of the person with whom she wants to communicate. After she has communicated hunger, there is a need for her to be fed.

The second process is one of representing how activities or tasks fit together. This is a process of representing how large tasks can be decomposed into smaller components , and the logical relationship between these. A common technique used is called hierarchical decomposition, which means breaking larger activities into smaller activities until a sufficient level of detail is reached. A good way of achieving such decomposition is to repeatedly ask "how" questions to break activities into smaller units.

Effective human-centered task analysis requires close personal contact between members of the design team and the people who will actually be using the system. Both ends of this link can be difficult to achieve. Understanding of the users themselves is also important. Knowing the users' backgrounds will help the designer to know what features the system should provide. Less quantifiable differences in users, such as their confidence, their interest in learning new systems, or their commitment to the design's success can affect decisions such as how much feedback to provide or when to use keyboard commands instead of on-screen menus , for example.

Task analysis can be illustrated by going through the interface of TiVo [11] (see Figure 4.3), which though narrow and simple, addresses the design of a product and interface to record television programs (thereby taking on the task of capturing the ones you want). It makes it easy for you to specify which types (by show title, time, or subject), and which episodes ( next , all). It dials out on a modem and through the Internet to determine the schedule, and then it traps the signals coming in on cable or antenna to its disk for you. You delegate the work of recording the show to the device, by selecting it from the menu, as you would select a nice steak in a restaurant and delegate the cooking of it. This is a me-centric appliance.

[11] http://www.tivo.com/

Figure 4.3. The TiVo System

graphics/04fig03.jpg

After establishing a good understanding of the users and their tasks, a more traditional design process might abstract away from these facts and produce a general specification of the system and its user interface. Then you should try to find existing interfaces that work for users and build ideas from those interfaces into your systems as much as practically possible. The rough description of the design should be put on paper, which forces you to think about things. But it shouldn't be programmed into a computer (yet), because the effort of programming, even with the simplest prototyping systems, commits the designer to too many decisions too early in the process.

After thinking through the paper description of the design, it's time to build something more concrete that can be shown to users and that can act as a more detailed description for further work. In the early stages of a simple design, this concrete product might be as simple as a series of paper sketches showing the interface while a user steps through one of the representative tasks. A surprising amount of information can be gleaned by showing the paper mock-up to a few users. The mock-up may even reveal hidden misunderstandings among members of the design team.

No matter how much analysis has been done in designing an interface, experience has shown that there will be problems that appear only when the design is tested with users. The testing should be done with people whose background knowledge and expectations approximate those of the system's real users. The users should be asked to perform one or more of the representative tasks that the system has been designed to support.

The testing with users will always show some problems with the design. That's the purpose of testing: not to prove the interface, but to improve it. The designer needs to look at the test results, balance the costs of correction against the severity of each problem, and then revise the interface and test it again. Severe problems may even require a reexamination of the tasks and users.



Radical Simplicity. Transforming Computers Into Me-centric Appliances
Radical Simplicity: Transforming Computers Into Me-centric Appliances (Hewlett-Packard Press Strategic Books)
ISBN: 0131002910
EAN: 2147483647
Year: 2002
Pages: 88

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