Decision-making and predictive aids in discrete multi-stage decision tasks

In this thesis an attempt is made to identify the capabilities and limitations of the human decision-maker in multi-stage decision tasks and to investigate and evaluate methods of aiding him, particularly with the use of on-line predictive displays. In multi-stage decision tasks, the decisions already made by the decision-maker affect the decision-situations he will subsequently face. This requires that experimental studies of such decision-making must present equivalent interactive decision situations. Although the necessary methodology for such studies is rather complicated, the results thereby obtained are more relevant to many real-life situations. [Continues.

Developments in predictive displays for discrete and continuous tasks

The plan of the thesis is as follows: The introductory chapters review the literature pertaining to human prediction and predictive control models (Chapter 1), and to engineering aspects of predictive displays (Chapter 2). Chapter 3 describes a fundamental study of predictive display parameters in a laboratory scheduling task, Chapter 4 attempts to verify these findings using test data from an actual job shop scheduling problem. Chapter 5 branches into the area of continuous control with a pilot study of predictive displays in a laboratory simulated continuous stirred-tank chemical reactor. Chapter 6 uses the experience gained in the pilot study as the basis for a comprehensive study of predictive display parameters in a further laboratory study of a simplified dual-meter monitoring and control task, and Chapter 7 attempts to test the optimal design in a part-simulated semi-batch chemical reactor using real plant and experienced operators in an industrial setting. The results of the experimental programme are summarized for convenience in Chapter 8. Chapter 9 draws together the threads from the various experiments and discusses the findings in terms of a general hierarchical model of an operator's control and monitoring behaviour. Finally, Chapter 10 presents conclusions and recommendations from the programme of research, together with suggestions for further work

Towards the on-line development of visual interactive simulation models

Reviews of previous work on visual interactive simulation, and on the interface between humans and computers were undertaken, the latter considering the physical and psychological aspects of the subject. Two simulation projects carried out in association with Rolls-Royce Aero Engines and the British Steel Corporation are described in detail. As a result of these projects and the review of previous studies, a major weakness in the technology of visual interactive simulation was identified: while the visual representation aids validation, verification, and experimentation, no facilities are provided to assist the analyst in the task of model construction. Simulation program generators are of proven use for non-interactive models, but a visual model requires a graphically oriented approach. The main section describes the design and implementation of a substantial extension to the simulation software developed at Warwick. This allows the design and development of displays to be carried out 'on-line', while preserving the one-to-one correspondence between simulation entities and their visual representation. It is suggested that this has the potential to significantly reduce the elapsed time taken to develop visual simulation models, while increasing the involvement of the user (or sponsor) in the modelling process, especially when 'pre-defined' entity types are used to minimise the amount of model- specific coding required. Finally, potential routes for the further development of visual interactive simulation are discussed, including the implementation of a 'simulation language' interpreter within the existing software. This would result in a system which was fully interactive, easing model development as well as experimentation