The objectives of this project were to:
-provide the Cognitive Design Aid (CDA), a software package incorporating the principles of cognitive psychology that could be used by a designer of a user interface to help assess human-machine cognitive compatibility
-prepare design guidelines derived during the development of the design aid
-to assess current trends in interface technology.
CDA incorporates modules based on principles extracted from cognitive psychology. These modules handle the inputs from designer to CDA. These inputs are a description of the interface and can vary from a general to a detailed level, depending on the stateof development of the design.
Interfaces which were well tested were used for validating the CDA. Their descriptions were input to the CDA, which provided cognitive compatibility indices. Human error performance was also directly measured from use of the interfaces. Four different indices were found to be strongly predictive of errors and were used in the CDA. The existing CDA is thus potentially highly useful for predicting errors. The final report also discusses possible future extensions and developments.
The CDA is supplemented with an operational description and a report describing the psychological foundations of the project.
The Design Guidelines operational description is intended for both designers and human factors specialists who require a comprehensive and accessible set of cognitive psychology design principles. The principles are presented with examples and areas of application in a manner which allows the relevant research to be traced. The design principles include those on which the CDA is based, and those for which automatic assessment by a CDA is not yet possible.
A report, Trends in Human-Computer Interface Technology, describes those developments, particularly in electronic office systems, that are relevant to cognitive compatibility. This information can be used for further development of the CDA and the next statement of design principles.
The experience gained during the project and presented in the project deliverables will have an impact on both academic and industrial practice. The power of the CDA to predict average user error for the interfaces chosen merits further research. If this is shown to be a general result, it will be of great importance for cognitive psychology and practical user-interface design.
During the development of the CDA the partners studied topics which will be highly useful to them and others in subsequent projects (for example, methods for interface description and evaluation). The Guidelines and Trends in Technology documents are already in use by the partners in their human factors work and, like all the reports in this project, are publicly available.
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