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3.3. EVALUATION
There are basically two types of evaluations: expert evaluation and user-driven evaluation. We conduct both of these evaluations with paper prototypes as well as computer prototypes. The expert evaluation is a method involving an expert in design guidelines (Skevik, 1994) which are based on principles of perception and cognition. The so-called user driven evaluation is a method based on cooperative evaluation with users (Wright and Monk, 1991). After years of performing these evaluations, we have developed a specific set of work roles for performing the evaluations and a question format for evaluating the design prototype afterwards.
We have also found it critical to formulate specific goals for the evaluations. For an evaluation conducted at a very early stage, the most important thing is to determine if the user can understand the conceptual idea behind the system. Later on, it is more important to determine if the user can perform a specific task, perhaps with a particular time constraint.
Following the use of our techniques, it is possible to determine if the system is appropriate for the users. This is our major goal for all evaluations performed, ranging from the first paper prototypes to the final delivery test. Some users are involved in the evaluations throughout the course of the project and some are involved only in selected evaluations.
4. BUBBLING TECHNIQUE
We have developed a technique called Bubbling that allows a quick launch into the design process (Nilsson and Lachonius, 1996). Bubbling makes use of a persons ability for quick associative thinking. All that is needed is a pen and paper. One begins by placing a key issue from the design space in a bubble in the middle of the paper as shown in Figure 6.8. That key issue can be a desired emotional response (from users) to the system, a user goal, a user category, a business goal, a task, or an information entity. For example, perhaps a goal is for the users to perceive the system as supportive.
Figure 6.8 Bubbling with a key issue.
After listing the key issue, the next step is to associate freely to that issue, drawing connecting bubbles as shown in Figure 6.9, until no further associations come to mind. Examples of possible associations to supportive are respectful, liking, controlled, helping hand, and lean against.
Figure 6.9 Bubbling associations.
The next step in Bubbling is to generate ideas on how to create one or more designs for each of the associated words. It is helpful to ask questions such as What can I do to make the user able to do/feel...?, What should I do to counteract the users tendency to do/feel...? (see Figure 6.10 for some Bubbling design ideas). The ideas can be conceptual, functional, or graphical. The important thing is to base the process of generating ideas on the design space. Examples of design ideas for the associated phrase helping hand are:
Figure 6.10 Bubbling do's and don'ts.
This technique should provide a list of desirable design ideas as well as things to avoid in a design. It is also helpful to place the items in a list with separate columns for desirable and undesirable ideas. They can then be compared for potential conflicts (an idea can be desirable in one situation but not in another) or for the possibility that several ideas support a similar concept.
To generate additional ideas, Bubbling can be used with other key issues. When ideas are no longer being generated, it may be time to combine them and to reflect on the alternative potential designs. It is important to avoid focusing too long on any particular detail. Instead, try to fit the design ideas into the design space in its entirety. Bubbling is most helpful in decomposing the design space into smaller components and getting started toward a useful design. It is also important to sketch during Bubbling. This will help to communicate the ideas and to generate even more.
Bubbling can be done alone or in cooperation with others. When doing it with others, a group can do it together or each member can take one key issue each and work with it by themselves. Group members can then trade issues after all associations have been generated with a particular issue. The Bubbling technique is part of one of our methods for usability work, called VISA.
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