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User Centered Design

Interface design should begin with the user and the reasons they are using the product. As Negroponte says, "Why can't telephone designers understand that none of us want to dial a telephone? We want to reach people on the telephone!"

We are at a place in history where we are adapting computers to human needs by replicating human features into processes and systems and by researching the cognitive, linguistic, and psychological events of humans.

Interface design goes beyond static screens with no color or moving elements. Interface design is shifting metaphors and designing products from a holistic perspective (Saba, 1995).

Don Norman says, "Every interface designer is a system designer" (Laurel, 1991). This system can include utilizing constructivist learning theories to provide users with new ways of thinking about books, classrooms, and learning (Cunningham, 1993).

Future interfaces can provide learners with interfaces allowing them to collaborate with other students on a project; products that give a user the ability to develop their own links throughout a hypertext book to create meanings for themselves; interfaces that provide an expert at your fingertips to clarify or restate a theory.

Designs will incorporate new modalities such as spoken language as well as advanced graphical techniques such as animation and virtual reality. The future of interface design is a total system.

Every element in the design process plays a part in the development of the interface, from the kind of hardware, content, and the people developing the product.

However, no matter how technologies change over the next five years, the systematic ways of studying people is still going to be the key to success of interface designs (Laurel, 1993).

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Interface Design in a Hypertext Environment

When designing an interface you must keep in mind ease of use and a users ability to navigate successfully through the information.

A user can get disoriented easily when using a hypertext document so you want an intuitive and logical organization of information.

You want people to be able to use your product without much prior training. Therefore, when designing an interface three of the most important issues are:

• identifying users' needs;
• generating a metaphor;
• creating a functional model.

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Design Phases

The conceptualization phase includes a task analysis.

A task analysis identifies your specific users' needs, their tasks and or topics. It is critical to a successful design to understand the total system of how, when, what, and where the information is accessed and used.

Design decisions should be made considering this identified audience. Users can be brought into the design process early by conducting focus groups using storyboards to illustrate the interface design. This early evaluation prototyping process can introduce valuable information and save time (Laurel, 1993).

Generating a metaphor introduces and familiarizes the user with the structure and organization of the information. Metaphors help relate prior knowledge to new information (Gordon pg. 154) and anchor new information to old information. This gives a learner an opportunity as Gagne (1985) would say to selectively encode the information for future retrieval.

The graphics related to this metaphor also play a key role in conveying information. Graphics capture the user's attention and help them process relevant information (Gordon pg. 154-155) and the metaphor gives you the structure to "chunk" and logically group information for the learner (as cited in Fleming, 1993).

The user is then able to quickly scan the table of contents for the desired information and obtain it. Building an intuitive product is an important part of using a metaphor because the user is already familiar with the structure of the design.

Creating a functional model or rapid prototyping (as cited in Gordon, 1995) is a primary issue in interface design today. However, rapid prototyping can be as simple or complicated as you or your client desires.

There are several products available today giving designers the power to develop a prototype in just a few days. Since rapid prototyping has become so easy, usability testing has become even more important.

This formative evaluation or testing of a product design provides valuable information in the early stages of the design process. This feedback allows the designer opportunities to easily improve and change the interface saving time and money.

Prototyping can include either a basic storyboard or sketch of what a typical screen could look like or it could include a few branching buttons to other content areas in a computer based application or could be totally interactive piece of software (Gordon, 1995).

Prototypes are believable models of what you may want your real thing to look like, but more importantly prototyping is cost effective and is an efficient way of developing a usable interface. Important features of rapid prototyping are:

• ability to get feedback from the user early in design phases;
• ability to redesign user interface according to users needs and expectations;
• saves time and money;
• aids in developing a more user friendly product;
• allows users to try out the interface.

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Usability Testing

Usability testing is matched perfectly with rapid prototyping because it can be done simultaneously.

For example Sun began usability early in the design phase by asking users for feedback about their color paper based interface mockup. Another interesting formative test Sun conducted was a card sorting activity. They wrote concepts on index cards and had the users sort similar concepts into the same pile (Nielsen, 1995).

This activity provides the user an opportunity to chunk and organize information according to their perceptions (Fleming, 1993) and provides the designer with insight into their mental model (Nielsen, 1995).

Sun also filmed a person navigating through the prototype. Using two cameras they captured the computer screen and the second camera focused on the user recording their interactions.

Analysis of the video content is conducted to gain quantitative information, such as counting the number of test subjects who finish a particular task, or how long each task takes, or how many errors each makes, or how many questions asked while performing the task.

Testing can also be qualitative such as comments from the test subjects while performing tasks or observations of the test team. Data can be collected on the following:

• task completion time,
• task success rate,
• user satisfaction,
• user product preference.

There is also data logging software that can track the clicks of a person in a particular software program giving you the completion rates of tasks. Test goals should be specific, not general as in "testing if it works." There are four types of usability testing:

• Formative Evaluation is done early in a project helping to guide the design development.
• Summative Evaluation is done when a project is complete.
• Comparative Evaluation compares two ways of presenting the same information.
• Protocol Analysis asks users to speak their thoughts either while performing a task (concurrent verbalization) or after (retrospective verbalization).

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Instructional Strategies

Some other important instructional strategies when designing an interface is organizing information into consistent segments, presenting chunks or units of information and presenting concepts using multiple, complementary symbols, formats, and perspectives all which improves learning (Hannafin, 1993).

In hypertext it is important to use visual markers. Visual markers or symbols allows the user to determine where he/she is at within that document.

This helps alleviate what Kerr (as cited in Fleming, 1993) calls the "wayfinding problem." Giving a user visual clues within a hypertext document or web site is critical to their ability to successfully navigate through that virtual space.

Upfront organizers and visual clues help the user orient themselves and make mental maps of the information. For example, by providing a visual marker such as a signature bar the user can determine where he/she is in the document at any given point. It is important to incorporate these points into the interface design.

Consistency is also critical as Tullis states (as cited in Gordon, 1994) "based on knowledge of the location of some items on the screen, one should be able to predict the locations of others" and that is achievable through using consistent page design.

A concern in web design is the user may not always come into a document from the top or home page. The user may do a search on the web and pull up a document in the middle of its hierarchical structure.

It is critical to give the user tools to navigate within that document without regard to the browser's navigational tools. Providing consistent navigational buttons on each page, the user can always get to the top or home page of the document.

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Interface, Hypertext and the Future

Hypertext through the World Wide Web (WWW) links us to the world. It links us to people we have never met before and to real experiences we could previously only read about.

The Internet's WWW relies upon hypertext to disseminate information and interface design is a critical element to it's success.

We are at a point in history where information can be disseminated at a pace before unknown to man. Over the past four years the Internet has changed our reality.

The rate of growth is exciting, Forrester Research states, "By 2002, 43% of U. S. households will have access and over 320 million worldwide will be online by 2002."

One final note, no matter how technologies change in the future, the systematic ways of studying people are still going to be the key to successful interface/hypertext designs (Laurel, 1993).

The future is here, let's put on our best "interface".

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References

Cunningham, D. J., Duffy, T. M., & Knuth, R. A. (1993). Textbook of the future.

C. McKnight, A. Dillon, & J. Richardson (Eds.), Hypertext: A psychological perspective, (pp. 19-49). NY:

Ellis Fleming, M., & Levie, W. H. (1993). Instructional message design. Englewood Cliffs, NJ: Educational Technology Publications.

Gagne, R. M., & Merrill, M. D. (1990). Integrative goals for instructional design. Educational Technology Research & Development, 38(1), 23-30.

Gordon, Sallie E. (1994). Systematic training program design: maximizing effectiveness and minimizing liability. Englewood Cliffs, NJ: Prentice Hall.

Park, I. & Hannafin, M. J. (1993). Empirically-based guidelines for the design of interactive multimedia. Educational Technology Research and Development, 41 (3), 63-85.

Laurel, B. (1991). Introduction. In The art of human-computer interface design (B. Laurel, Ed.). Menlo Park, CA: Addison Wesley Publishing Company, Inc.