This thesis suggests that there is a problem with technology transfer in crop production. The nature of the problem and the mechanisms available to the agricultural research sector for solving it are examined. As a consequence it is argued that Decision Support Systems (DSS) technology is an extremely useful mechanism for encapsulating and delivering scientific knowledge to the industry. The thesis then poses the question of why this technology is not currently being taken up by farmers and farm consultants, hypothesising that the current lack of user involvement in design is a major contributing factor. The hypothesis is supported by a survey of DSS development and use in agriculture and it is concluded that a user-centred design (UCD) approach is important to the successful adoption of these systems by the industry. The thesis then asks what methods the agricultural DSS developers should employ to ensure a user-centred design approach. It is suggested that it is not sufficient merely to point DSS producers in the direction of user centred design but to furnish them with adequate methods and tools to achieve this goal, bearing in mind their specific requirements and limitations and the nature of the decision support task. A review of currently available methods reveals that none of the standard methods meets this requirement and that a new approach is therefore needed. An approach supported by work from management science is introduced. This approach identifies the user's questions to the system as a means of defining its function and features. Its use in the context of workshops is developed into a user centred design method to meet all of the requirements for the designer stakeholders. The question approach is also used as the basis of ä method for identifying DSS interface requirements and collating design solutions. Both methods are presented as mechanisms for improving the acceptance of DSS in the sector. The document concludes by discussing the contribution made by the thesis to its originating disciplines and looks forward to the future of DSS technology in crop production.

No description available.

The aim was to formulate ergonomics criteria to assist in the design and evaluation of various commonly used packages so that they are well adapted to the needs, capabilities and limitations of consumers. The consumers used in the study included male and female able-bodied subjects, some of whom were elderly; and the disabled, who suffered from arthritis, Parkinson's disease, cerebral palsy, multiple sclerosis, or one-handed function (hemiplegics or amputees). The design criteria took the form of normative data. These were derived, by experiment, with subjects handling specially designed apparatus which closely simulated the characteristics of real packages. The norms were the torques and forces that the weak, average and strong subjects could exert on a range of packages. The norms were related to the breaking torques and breaking forces of packages found in the market place. It was shown that many of these packages require opening torques and forces which are well beyond the capabilities of the weaker sections of the sample. New methods for representing the torques which people can exert were derived, involving the calculation of ratios of centiles between and within groups for comfortable and maximum exertions of torque. It is suggested that this method, which has considerable promise, be further validated in future studies involving not only the description of forces and torques, but also that of the reaches, carrying and lifting capacity, the articulation, pushing and pulling capacity, and physical endurance of human subjects. The promise lies in the short-hand derivation of the capabilities of weaker segments of the population, who are difficult to obtain in large numbers, from studies involving small samples from the fit and able population.

This thesis considers the application of ergonomics in Industrially Developing Countries (IDCs) with a particular focus on rural subsistence agriculture in Ghana. The thesis had two aims, firstly to identify the need for ergonorMcs to be incorporated into international development projects. A survey of the causes and incidence of illhealth in subsistence fanning was undertaken A high incidence of occupational disorders was recorded with injuries Erom. handtools and lower back pain being endemic. This survey was followed by a checklist analysis and Participatory Rural Appraisal of agroprocessing. Ergonomics issues were identified in many agroprocessing activities. These included poor posture, repetitive motions, manual handling, and stressful work environments. Inappropriate technology transfer was widespread. Farmers behaviour when working in high ambient temperatures was investigated in the field. Whilst methodological problems were encountered and discussed, heat stress was considered a potential problem that deemed further investigation. From the surveys and field investigation, ergonorMcs problems in human work in rural subsistence agriculture were identified and a need for ergonotMcs to be incorporated into development projects was demonstrated. In the light of this, the second aim of the thesis was addressed, investigating the appropriateness of tools, methods and standards for use in IDCs with an ergonomics tool kit being developed. Following on from the field investigation into working in the heat, stratergies for assessing heat stress in tropical agriculture were assessedin terms of their validity and usability. In a simulated tropical agricultural task heat stress standards (ISO 7243 and ISO 7933) were found to be valid if over protective. It can be anticipated that the ISO 7243 can be easily used in IDCs. The usability of ISO 7933 however was questioned. As the standards failed to accommodate for solar load, solar radiation and its effects on the human thermoregulatory system were considered. Six subjects performed a step test in outdoor conditions with a solar load, repeating this in similar conditions in a thermal chamber with no solar load. The difference in sweat loss between the conditions was attributed to the increased load from solar radiation. In the conditions measured, the radiation incident on the human thermoregulatory system was 82W/M 2. Two existing models for solar radiation were validated. Subjective and objective ergonomics tools were assembled in a tool kit that was used on an ad hoc basis in the field in Ghana. A pragmatic approach to the usability of the tool kit was adopted. Drawing on practical experiences and expert analysis, it was found that simple, reliable, robust and easy to maintain equipment was most appropriate and usable in the field. Subjective rating scales proved to be difficult to use and were unreliable. Participatory rural appraisal methods were found to be simple, rapid and well suited to ergonomics research in tropical agriculture. Practical implications from the research in Ghana were discussed and recommendations made. The thesis concluded that there is a need for ergonomics interventions in IDCs with the ergonomics tool kit being generally acceptable for use in this field. The thesis concluded that there is a need for ergonormcs and that the tools, methods and standards considered were found to be generally usable, although the approach often required adapting to local circumstances whilst maintaining scientific integrity.

No description available.

The general aim of the work reported in this thesis is to investigate the viability of applying theories and principles from the field of natural language pragmatics to that of human-computer interaction. In pursuing this aim, the research falls broadly into three phases. The first of these is the exploitation and adaptation of the Gricean Cooperative Principle, its maxims and inferential rules to situations of computer use which do not employ natural language as the medium of communication. The purpose of this endeavour is to provide a novel and revealing analysis of non natural language interaction and to establish principles for dialogue design, the application of which enhance the quality of communication between system and user in such situations. The second phase concerns the application of the adapted Gricean principles to the design of a dialogue management system, intended to address some of the problems which other research has revealed users to experience in using the standard UNIX® shell interface. This second phase resulted in the production of the QDOS system, which is both a simulation of part of the UNIX® file system and an implementation of the proposed dialogue management system. This software acts as the vehicle for all subsequent evaluative exercises constituting the third phase. This takes the form of an evaluation of the QDOS system and its theoretical underpinning, based on a two-condition experiment and a protocol analysis, involving a number of experimental subjects. This research provides an original application of the Gricean Cooperative Principle in human-computer interaction and a theoretical and practical demonstration of the validity of this endeavour. It also adduces an analysis of the UNIX® interface and its vagaries in terms of a principled and consistent set of criteria as well as identifying a significant class of dialogue breakdown, the circumstances and incidence of which cut across issues of interface style.

No description available.

The discipline of Human Computer Interaction (HCI) was established in the early 1980's on the foundations of cognitive psychology, computer science and ergonomics. In recent years however, claims have been made for the relevance of forms of sociology to this avowedly multidisciplinary field, and a number of sociologists have attempted to contribute to the general enterprise of developing a deeper understanding of the computer user and thereby informing, and improving, software design. This thesis is, in one sense, a continuation of this emerging body of work. However, my contention is that little, if any, critical attention has been given within this work to questions that would seem to be of fundamental importance to attempts at collaboration between disciplines: how is the disciplinary organization of knowledge to be understood, and more specifically, can HCI be adequately described in the simple pluralist terms in which it tends to characterise itself? The primary focus then is on the discipline of HCI. Utilising a theoretical model which considers disciplines as distinctive discourses which constitute their own domains of objects, I analyse the discourse and practice of HCI in order to explicate some of its underlying premises and assumptions, and to argue that it has, unavoidably, set many of the parameters within which contributing disciplines must operate. Texts, audio and video tapes, and ethnographic observation of instances of HCI practice form the empirical basis of the thesis. In addition, an analysis of some recorded human-computer interactions, which like the study as a whole, exemplifies an approach that differs from the prevailing sociological models within the field, is used to support the argument.

The purpose of this study is to analyse and assess Chinese writing systems for visually impaired persons. The study provides a general description of the Chinese character script, the reform of Chinese language and the reform of Chinese character script. It reviews past and contemporary Chinese writing systems for visually impaired persons and gives a general description of the currently used Chinese writing systems for visually impaired persons. The different Chinese writing systems for visually impaired persons are discussed and the nature of the relationship between speech and writing in Chinese is taken into account. The discussion concludes that change to the existing writing systems for visually impaired persons is essential in order to provide for the full and equal participation of visually impaired persons in Chinese society and culture. The theoretical possibilities for achievable and worthwhile improvements to the systems are assessed. The assessment is set in a wider context by taking into account developments in other societies, notably Japan and Korea, where there are similarities in problems associated with non-alphabetic scripts. Developments in communications and computer technology and their relationship to visually impaired users are also considered. The results of field research conducted in China, Hong Kong, Taiwan and Britain are used to put these assessments into perspective. The field research constituted a pilot study since no previous such studies had been made. It was concerned with visually impaired users' perceptions of Chinese script and Chinese writing systems for visually impaired persons. The thesis of this work is that significant improvements could be brought about by changing Chinese writing systems for visually impaired persons. Key issues for such improvements are identified and a framework for change is established. To illustrate the framework and the issues which might arise in its implementation 1000 Chinese characters have been encoded with Braille symbols but no attempt has been made to achieve a comprehensive encoding. This could and should be left to bodies in China, entrusted with the detailed elaboration and practical implementation of the changes.

The research is concerned with the terminological problems that computer users experience when they try to formulate their knowledge needs and attempt to access information contained in computer manuals or online help systems while building up their knowledge. This is the recognised but unresolved problem of communication between the specialist and the layman. The initial hypothesis was that computer users, through their knowledge of language, have some prior knowledge of the subdomain of computing they are trying to come to terms with, and that language can be a facilitating mechanism, or an obstacle, in the development of that knowledge. Related to this is the supposition that users have a conceptual apparatus based on both theoretical knowledge and experience of the world, and of several domains of special reference related to the environment in which they operate. The theoretical argument was developed by exploring the relationship between knowledge and language, and considering the efficacy of terms as agents of special subject knowledge representation. Having charted in a systematic way the territory of knowledge sources and types, we were able to establish that there are many aspects of knowledge which cannot be represented by terms. This submission is important, as it leads to the realisation that significant elements of knowledge are being disregarded in retrieval systems because they are normally expressed by language elements which do not enjoy the status of terms. Furthermore, we introduced the notion of `linguistic ease of retrieval' as a challenge to more conventional thinking which focuses on retrieval results.