|Expanding Access to Science and Technology (UNU, 1994, 462 pages)|
|Session 4: Intelligent access to information: Part 1|
|Human-centred design of information systems|
In this section, three example applications are discussed: (1) maintenance information systems; (2) sales transaction systems; and (3) design information systems. The purpose of these illustrations is to show how human-centred design influences the nature of the products and systems that result.
3.1 Maintenance Information Systems
The application concerned the problem of transforming large, blueprint-size hard copy, often called C size, to small, computer-display-size images . The context of interest was helicopter maintenance.
A very important element of human-centred design is initial emphasis on defining the true nature of the problem to be solved. From the point of view of the humans involved in this context, the problem of interest was helicopter maintenance, not reading blueprints. Thus, in terms of validity the primary concern was providing information to support maintenance activities rather than finding a way to access blueprints on a small display.
This realization led us to focus on the tasks to be done rather than on the nature of blueprints. It became clear that information is used in different ways depending on the nature of the task, i.e., problem solving vs. procedure execution. This conclusion led us to adopt Rasmussen's abstraction-aggregation hierarchy  as a means of organizing maintenance information.
The abstraction dimension included physical form, physical function, and generalized function depicted in terms of location diagrams, schematics, and block diagrams, respectively. The aggregation dimension included assembly, subsystem, and system-level representations. As a consequence of this approach to organizing information, it was no longer necessary to have large displays.
This system concept was evaluated in a series of five experiments. It was determined that the nature of the displays affected maintainers' activities. They performed at least as well using the new displays and overwhelmingly preferred the new displays. Further, it was determined that creation and updating of the display database would be easier with the new approach. Thus, both acceptability and viability were improved.
3.2 Sales Transaction Support
Computer-mediated sales are an increasingly prevalent approach to selling in retail stores, banks, airlines, and many other domains. Perhaps not surprisingly, there has been considerable interest in improving the user-system interface of such systems. Of particular concern, because of the high turnover among people performing such jobs, has been decreasing or possibly eliminating the need for any extensive training in the use of these systems.
We undertook two efforts in this area, one in the domain of retail sales and the other in passenger reservation systems. In both cases, we were asked to improve the usability of these systems by focusing on the user-system interface. We employed the human-centred design methodology to pursue these efforts.
In both cases, we focused initially on viability, acceptability, and validity for a period of 4-6 weeks. We discovered that usability problems, while important, were by no means the predominant concern. The benefit sought in both cases was increased sales and the cost was the time required to make sales.
It would have been quite possible to solve usability problems without enhancing viability - increasing benefits and/or decreasing costs. Focusing solely on usability would have probably increased individual user acceptance but not necessarily organizational acceptance. Finally, solving usability problems alone might have met requirements, but would not have been a valid solution to the right problem.
For both efforts, the initial focus on viability, acceptability, and validity led to an emphasis on sales support rather than solely on improved operability of computer terminals. While usability and the user-system interface still received much attention, it was given in the context of supporting the tasks that really mattered. The result was system designs that were substantially different from those originally envisioned.
3.3 Design Information Systems
The application under design information systems focused on access to and utilization of science and technology information in the context of designing aerospace systems. The motivation for this effort included a long-term interest in the value of information [7, 11], as well as a practical need to develop design information systems.
In keeping with the human-centred approach to design, we began by focusing on viability, acceptability, and validity. These issues were pursued using questionnaires, interviews, and observational techniques involving a large number of designers . We found that very little science and technology information is accessed by formal means.
Why don't designers take advantage of science and technology information? One answer is that they perceive little benefit and great cost in accessing this type of information. They attach no benefit to using the information system per se.
They are concerned with making informed design decisions. They become informed by asking other people in their organization, a conclusion also reached by Allen . Why do they rely on subjective opinions rather than the "hard" objective information provided by science and technology? A primary reason is that they find published research results to be applicable in general but not to their specific problems in particular. They want contextually based answers to their questions rather than generic simplifications. In other words, they question the validity of available science and technology information.
There are also acceptability problems. Almost all science and technology information is created, written, and published for consumption by scientists and technologists. Designers seldom have the specialized expertise, or the patience, to penetrate this information. They find the context and format of presentation totally unacceptable.
The essense of the designer's dilemma is depicted in figure 2. Each transformation in this diagram requires time and effort. Both time and effort increase as one moves to the right in this diagram. It is easy to see why a designer would not want 1,000 abstracts of research articles on human memory to answer a question concerning usability of radar modes. The cost of answering questions in this way far outweighs the benefits.
The above conclusions concerning designers' perceptions of viability, acceptability, and validity caused us to focus on designers' tasks and information needs rather than on the nature of science and technology information. Thus, rather than focusing on how to get designers to access and utilize science and technology information, we looked at the information requirements to support design decision-making. Such requirements should drive the way in which science and technology information is created, organized, formatted, and accessed if this information is intended to support design.
After considering alternative representations, we concluded that information seeking in design could be represented as a process of asking questions and pursuing answers in the context of a "design space" including a set of archetypical tasks focused on attributes of the design artifact and characterized in terms of abstraction and aggregation . Typical scenarios or trajectories in the design space were studied to determine information requirements in particular and support requirements in general. Using a structured analysis and design methodology  led to identification of hundreds of requirements and an appropriate conceptual architecture that would satisfy these requirements.