Expert systems usability

Once one has built or acquired an expert system shell, an expert system is usable and useful at an early stage of development. Subsequent development consists of increasing and refining the knowledge, expanding the functionality and improving the efficiency of the system. 

Jonassen, D.H. (1991) Adding intelligence to Hypertext with expert systems and adding usability to expert systems with Hypertext. In this book. 

Adding Intelligence to Hypertext with Expert Systems and Adding Usability to Expert Systems with Hypertext... 

Many usability studies have pointed out that there is a considerable difference between involving so-called novice or expert users because these users may have different levels of experience with the system being evaluated. Therefore, it is important to study users over time as they develop expertise in using the systems to answer a key question of how the user s experience of a system s usability changes when they transform from being novices to being more expert, if usability problems really disappear over time when users get more familiar with a system [13]. This forms the motivation of the longitudinal nature of the reported study. 

The challenges for visualization are at least twofold. Easter graphics hardware will be required to display and manipulate more complex data displays. More importantly, the human effort required to develop visualization systems must be reduced. It is the realm of the expert programmer to implement a usable visualization system. General purpose tools that allow the nonexpert to import data in different formats into robust visualization systems are just beginning to appear. 

Analytic evaluation methods can be used early in the development process, well before there are users or prototypes available for empirical tests. Furthermore, it is often less expensive than making studies with users. Examples of analytic methods are heuristic evaluation, cognitive walkthroughs, usability-expert reviews, group design reviews [864, 1025]. A hazard of analytic evaluation is that system developers or software designers may feel that they are being evaluated [941]. 

Processing Characteristics of IQAP. To follow the experts methodology, it appears that the processing within IQAP will be performed in two steps. In the first step, the inputs should be accepted and a constraint-based system will develop a set of constraints and limits that apply to the data. The knowledge embedded in this first system will convert the constraints into an analytical method and the associated set of QC criteria. It is expected that because QA/QC Objectives incorporate considerations regarding the usability of the data, the constraints will be flexible enough to process the inputs into a reasonably structured set of data tables. Therefore, in the second step, the method and its associated QC criteria will be represented in a relational database. The level of detail in the specifications of the QC criteria and the relationships between the data elements will be more specific as the process proceeds from the first step to the second step. 

Our initial objective in the development of ACexpert, was to develop a system that could offer expert assistance during the analysis of metals. We also intended that the modules developed here for atomic absorption spectrometry would become more generally usable for analysis by other instruments. 

There are advantages and disadvantages to each of these evaluative techniques (see Table 8) (Preece 1993, Karat 1997). Thus, a combination of methods is often used in practice. Typically, one would first perform an expert evaluation (e.g., heuristic evaluation) of a system to identify the most obvious usability problems. Then user testing could be conducted to identify remaining problems that were missed in the first stages of evaluation. In general, a number of factors need to be considered when selecting a usability-evaluation technique or a combination thereof (see Table 9) (Dix et al. 1993 Nielsen 1993 Preece 1993). 

In the expert review process a suitable expert is provided with access to the target system or prototype and their view on the product s usability strengths and weaknesses is solicited. The review can occur at any point in the development process and whilst the technique is not a substitute for formal usability testing it is simple, structured and easy to learn. 

Usability experts User interface designers Cognitive psychologists Clinicians System trainers Business analysts Writers... 

The assessors might be experts in design or usability but fundamentally they are not real users of the system. Actual users are likely to have a different set of skills, come from a range of backgrounds and perhaps have a different level of understanding of the system. 

Identilying stakeholders— individuals or organizations who stand to gain or lose from the success or failure of a system— is also critical. Stakeholders include customers or clients (who pay for the system), developers (who design, construct, and maintain the system), and users (who interact with the system to get their work done). For interactive systems, users play a central role in the elicitation process, as usability can only be defined in terms of the target user population. Users themselves are not homogeneous, and part of the elicitation process is to identify the needs of different user classes, such as novice users, expert users, occasional users, disabled users, and so on. 

The TCAS example is very instructive it shows that a formal specification can be written for a system whose complexity defied expression in natural language and that formal specification was usable by reviewers and implementors who were not experts in the specification techniques used. 

User simulation testing is a mixture between a system level test focused on effective use of the software, and an expert usability test. High profile testers assume the role of end users and test the software following real protocols and procedures mimicking the real-use environment of the system. The focus of the test is... 

Oncoming vehicle information systems for PTWs, based on vehicle-to-PTW communication, is seen by experts as a basic system for a complete ITS-safety system for all road users . However, they think that it should be safe against hackers. It is considered to have deployment potential, as well as being appealing to road authorities. The usability issues are of critical importance, and drivers may choose to switch off/over-ride the system. 

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