Scenario Development and Practical Decision Making under Uncertainty: Application to Requirements Engineering

In this paper, we address the question of how flesh and blood decision makers manage the combinatorial explosion in scenario development for decision making under uncertainty. The first assumption is that the decision makers try to undertake ‘robust’ actions. For the decision maker a robust action is an action that has sufficiently good results whatever the events are. We examine the psychological as well as the theoretical problems raised by the notion of robustness. Finally, we address the false feeling of decision makers who talk of ‘risk control’. We argue that ‘risk control’ results from the thinking that one can postpone action after nature moves. This ‘action postponement’ amounts to changing look-ahead reasoning into diagnosis. We illustrate these ideas in the framework of software development and examine some possible implications for requirements analysis.     

‘Working Well, Together’: Arts-Based Research and the Cultural Future of Small Cities

This article offers a research update on a 3-year programme initiated by the Kamloops Art Gallery and the University College of the Cariboo in Kamloops, British Columbia. The programme is supported by a ‘Community–University Research Alliance’ grant from the Social Sciences and Humanities Research Council of Canada, and the collaboration focuses on the cultural future of small cities – on how cultural and arts organisations work together (or fail to work together) in a small city setting. If not by definition, then certainly by default, ‘culture’ is associated with big city life: big cities are equated commonly with ‘big culture’; small cities with something less. The Cultural Future of Small Cities research group seeks to provide a more nuanced view of what constitutes culture in a small Canadian city. In particular, the researchers are exploring notions of social capital and community asset building: in this context, ‘visual and verbal representation’, ‘home’, ‘community’ and the need to define a local ‘sense of place’ have emerged as important themes. As the Small Cities programme begins its second year, a unique but key aspect has become the artist-as-researcher. Correspondence and offprint requests to: L. Dubinsky, Kamloops Art Gallery, 101–465 Victoria Street, Kamloops, BC V2C 2A9 Canada. Tel.: 250-828-3543; Email: ldubinsky@museums.ca     

SymGeons: A Prototype Model of Visual Complexity with Implications For Visual Control Tasks

The way in which humans perceive and react to visual complexity is an important issue in many areas of research and application, particularly because simplification of complex matter can lead to better understanding of both human behaviour in visual control tasks as well as the visual environment itself. One area of interest is how people perceive their world in terms of complexity and how this can be modelled mathematically and/or computationally. A prototype model of complexity has been derived using subcomponents called ‘SymGeons’ (Symmetrical Geometric Icons) based on Biederman’s original Geon Model for human perception. The SymGeons are primitive shapes which constitute foreground objects. This paper outlines the derivation and ongoing development of the ‘SymGeon’ model and how it compares to human perception of visual complexity. The application of the model to understanding complex human-in-the-loop problems associated with visual remote control operations, e.g. control of remotely operated vehicles, is discussed.     

Rule-based document structure understanding with a fuzzy combination of layout and textual features

Document image processing is a crucial process in office automation and begins at the ‘OCR’ phase with difficulties in document ‘analysis’ and ‘understanding’. This paper presents a hybrid and comprehensive approach to document structure analysis. Hybrid in the sense that it makes use of layout (geometrical) as well as textual features of a given document. These features are the base for potential conditions which in turn are used to express fuzzy matched rules of an underlying rule base. Rules can be formulated based on features which might be observed within one specific layout object. However, rules can also express dependencies between different layout objects. In addition to its rule driven analysis, which allows an easy adaptation to specific domains with their specific logical objects, the system contains domain-independent markup algorithms for common objects (e.g., lists). Received June 19, 2000 / Revised November 8, 2000     

Decision Making and Management of Dynamic Risk

Managing dynamic environments often requires decision making under uncertainty and risk. Two types of uncertainty are involved: uncertainty about the state and the evolution of the situation, and ‘openness’ of the possible actions to face possible consequences. In an experimental study on risk management in dynamic situations, two contrasted ‘ecological’ scenarios – transposed from effective situations of emergency management – were compared in order to identify the impact of their ‘openness’ in the subjects’ strategies for decision making. The ‘Lost Child’ scenario presented qualitative and irreversible consequences (child’s death) and high uncertainty; it exerted high demands both in risk assessment (risk representation) and action elaboration and choice. A less open situation (‘Hydrocarbon Fire’) required a main choice between two contrasted actions, with quantitative computable consequences. The strategies of ‘experimental subjects’ (university students) and ‘operative subjects’ (professional fire-fighter officers) were compared in order to evaluate the ecological validity of experimental research in this field, from the point of view of the subjects themselves. The two scenarios appeared to be independent, so that quite different models of decision making have to be hypothesised, differing by the importance of assessing risk and defining possible actions on the one hand, and by the process of choice on the other. ‘Experimental’ subjects dramatically differed from ‘operative’ subjects when confronted with the same scenario, particularly for the less technical but more demanding scenario. It is hypothesised that three components might account for the effect of the situations and for the differences between and within groups of subjects: importance of situation assessment, spatial abilities, and global orientation of activity in managing dynamic risk.     

遥感影像空间分治快速匹配

目的 图像匹配是遥感图像镶嵌拼接的重要环节,图像匹配技术通常采用两步法,首先利用高维描述子的最近和次近距离比建立初始匹配,然后通过迭代拟合几何模型消除错误匹配。尽管外点过滤算法大幅提高了时间效率,但其采用传统的两步法,构建初始匹配的方法仍然非常耗时,导致整个遥感图像拼接的速度提升仍然有限。为了提高遥感图像匹配的效率,本文提出了一种基于空间分治思想的快速匹配方法。方法 首先,通过提取图像的大尺度特征生成少量的初始匹配,并基于初始匹配在两幅图像之间构建成对的分治空间中心点;然后,基于范围树搜索分治空间中心点一定范围内的相邻特征点,构造成对分治空间点集;最后,在各个分治空间点集内分别进行遥感图像特征的匹配。结果 通过大量不同图像尺寸和相对旋转的遥感图像的实验表明,与传统的和其他先进方法相比,本文方法在保证较高精度的同时将匹配时间缩短到1/1001/10。结论 利用初始种子匹配构建分治匹配中心以将图像匹配分解在多个子区间进行的方法有助于提高遥感影像匹配的效率,该算法良好的时间性能对实时遥感应用具有实际价值。     

Socio-Technical and Soft Approaches to Information Requirements Elicitation in the Post-Methodology Era

The contributors to this special issue focus on socio-technical and soft approaches to information requirements elicitation and systems development. They represent a growing body of research and practice in this field. This review presents an overview and analysis of the salient themes within the papers encompassing their common underlying framework, the methodologies and tools and techniques presented, the organisational situations in which they are deployed and the issues they seek to address. It will be argued in the review that the contributions to this special edition exemplify the ‘post-methodological era’ and the ‘contingency approaches’ from which it is formed.     

Effective Communication in Requirements Elicitation: A Comparison of Methodologies

The elicitation or communication of user requirements comprises an early and critical but highly error-prone stage in system development. Socially oriented methodologies provide more support for user involvement in design than the rigidity of more traditional methods, facilitating the degree of user–designer communication and the ‘capture’ of requirements. A more emergent and collaborative view of requirements elicitation and communication is required to encompass the user, contextual and organisational factors. From this accompanying literature in communication issues in requirements elicitation, a four-dimensional framework is outlined and used to appraise comparatively four different methodologies seeking to promote a closer working relationship between users and designers. The facilitation of communication between users and designers is subject to discussion of the ways in which communicative activities can be ‘optimised’ for successful requirements gathering, by making recommendations based on the four dimensions to provide fruitful considerations for system designers.     

Multipass hierarchical stereo matching for generation of digital terrain models from aerial images

This paper presents a new multi-pass hierarchical stereo-matching approach for generation of digital terrain models (DTMs) from two overlapping aerial images. Our method consists of multiple passes which compute stereo matches with a coarse-to-fine and sparse-to-dense paradigm. An image pyramid is generated and used in the hierarchical stereo matching. Within each pass, the DTM is refined by using the image pyramid from the coarse to the fine level. At the coarsest level of the first pass, a global stereo-matching technique, the intra-/inter-scanline matching method, is used to generate a good initial DTM for the subsequent stereo matching. Thereafter, hierarchical block matching is applied to image locations where features are detected to refine the DTM incrementally. In the first pass, only the feature points near salient edge segments are considered in block matching. In the second pass, all the feature points are considered, and the DTM obtained from the first pass is used as the initial condition for local searching. For the passes after the second pass, 3D interactive manual editing can be incorporated into the automatic DTM refinement process whenever necessary. Experimental results have shown that our method can successfully provide accurate DTM from aerial images. The success of our approach and system has also been demonstrated with a flight simulation software. Received: 4 November 1996 / Accepted: 20 October 1997     

MABA-MABA or Abracadabra? Progress on Human–Automation Co-ordination

In this paper we argue that substitution-based function allocation methods (such as MABA-MABA, or Men-Are-Better-At/Machines-Are-Better-At lists) cannot provide progress on human–automation co-ordination. Quantitative ‘who does what’ allocation does not work because the real effects of automation are qualitative: it transforms human practice and forces people to adapt their skills and routines. Rather than re-inventing or refining substitution-based methods, we propose that the more pressing question on human–automation co-ordination is ‘How do we make them get along together?’ Correspondence and offprint requests to: S. W. A. Dekker, Department of Mechanical Engineering, IKP, Link?ping Institute of Technology, SE - 581 83 Link?ping, Sweden. Tel.: +46 13 281646; fax +4613282579; email: sidde@ikp.liu.se     

Exploring agent support at the user interface in e-commerce applications

In this paper, we present some of the results from our ongoing research work in the area of ‘agent support’ for electronic commerce, particularly at the user interface level. Our goal is to provide intelligent agents to assist both the consumers and the vendors in an electronic shopping environment. Users with a wide variety of different needs are expected to use the electronic shopping application and their expectations about the interface could vary a lot. Traditional studies of user interface technology have shown the existence of a ‘gap’ between what the user interface actually lets the users do and the users’ expectations. Agent technology, in the form of personalized user interface agents, can help to narrow this gap. Such agents can be used to give a personalized service to the user by knowing the user’s preferences. By doing so, they can assist in the various stages of the users’ shopping process, provide tailored product recommendations by filtering information on behalf of their users and reduce the information overload. From a vendor’s perspective, a software sales agent could be used for price negotiation with the consumer. Such agents would give the flexibility offered by negotiation without the burden of having to provide human presence to an online store to handle such negotiations. Published online: 25 July 2001     

Features of Decision-Making in Process Control Tasks: The Relevance of the Work Context

This paper is centred on evaluating some significant features of decision-making in process control tasks. The study was carried out in a petrol refinery, specifically, with distillation console operators. Operator verbalisations were recorded during the completion of two specific tasks and later categorised by raters using a list of cognitive categories. The inter-rater reliability was calculated together with qualitative evaluations of the main overlaps among the categories. From the raters’ evaluations, flow diagrams were drawn that represented the plans and tactics developed by operators and the implied cognitive processes (evaluation, prediction, action, etc.). We found that the operators began the tasks with a primary global situation assessment that determined the choice of whether to cope with the task ‘step by step’ or ‘globally’. The results showed two patterns of decision sequences made in normal adjustment performance or in problem situations. Other findings are related to the importance of characteristics such as prediction, anticipation, feedback and the role of the alarms selected by a situation assessment and individual characteristics.     

Requirements Management: A Cinderella Story

Why do the business requirements and the final software product often have little in common? Why are stakeholders, developers and managers reluctant to embrace a full requirements process? Why does everybody say, ‘We don’t have time for requirements’? Why is the potentially most beneficial part of the development process ignored or short-changed?  Following are some observations about why the real requirements for the product often go undiscovered. We will address this by focusing on the different concerns of the people involved in requirements.     

Frame rate as a QoS parameter and its influence on speech perception

The preservation of QoS for multimedia traffic through a data network is a difficult problem. We focus our attention on video frame rate and study its influence on speech perception. When sound and picture are discrepant (e.g., acoustic ‘ba’ combined with visual ‘ga’), subjects perceive a different sound (such as ‘da’). This phenomenon is known as the McGurk effect. In this paper, the influence of degraded video frame rate on speech perception is studied. It is shown that, when frame rate decreases, correct hearing is improved for discrepant stimuli and is degraded for congruent (voice and picture are the same) stimuli. Furthermore, we studied the case where lip closure was always captured by the synchronization of sampling time and lip position. In this case, frame rate has little effect on mishearing for congruent stimuli. For discrepant stimuli, mishearing is decreased with degraded frame rate. These results indicate that the stiff motion of lips resulting from low frame rate cannot give enough labial information for speech perception. In addition, the effect of delaying the picture to correct for low frame rate was studied. The results, however, were not as definitive as expected, because of compound effects related to the synchronization of sound and picture. Finally, we inspected the still pictures of normal Japanese speech and determined a lower limit of frame rate from the view point of assisting hearing.     

Exploring the Suitability of Virtual Environments for Safety Training: Signals, Norms and Ambiguity in a Simulated Emergency Escape

This study aims at exploring the suitability of virtual environments for safety training in large public spaces. A virtual library was constructed which simulated many of the physical and normative characteristics of the ‘real’ university library which was the target of the virtual safety training project. In the virtual library, two different types of signals (fixed red signs vs. moving green arrows) for guiding people to the emergency exits were presented, and their efficacy on escape times was tested in three different conditions, differing with respect to the distance of participants from the escape exits (measured according to the number of corners separating participants from direct visual discovery of the emergency exit). No significant differences between the different kinds of signals were found, whereas surprising discrepancies among the three conditions appeared. The differences in performance in the three conditions were contingent upon the presence in the virtual library of peculiar environmental features embodying social norms – like a red ribbon indicating no transit. Uncertainty about the sense of such normative features in the context of the simulated emergency made some participants prone to peculiar knowledge-based errors consisting of inadequate sense-making of the normative aspects of the ongoing situation. This kind of error shows that the simulation succeeded in capturing one of the crucial characteristics of ‘real’ social context: ambiguity, which mostly depends on the fact that the social norms structuring public spaces and defining their legitimate uses are often ill defined and context dependent. Every valid experience in safety training requires coping with ambiguity in situations.     

A local method for contour matching and its parallel implementation

This paper presents a local approach for matching contour segments in an image sequence. This study has been primarily motivated by work concerned with the recovery of 3D structure using active vision. The method to recover the 3D structure of the scene requires to track in real-time contour segments in an image sequence. Here, we propose an original and robust approach that is ideally suited for this problem. It is also of more general interest and can be used in any context requiring matching of line boundaries over time. This method only involves local modeling and computation of moving edges dealing “virtually” with a contour segment primitive representation. Such an approach brings robustness to contour segmentation instability and to occlusion, and easiness for implementation. Parallelism has also been investigated using an SIMD-based real-time image-processing system. This method has been validated with experiments on several real-image sequences. Our results show quite satisfactory performance and the algorithm runs in a few milliseconds. Received: 11 December 1996 / Accepted: 8 August 1997     

Cooperation, Coordination and Interpretation in Virtual Environments: Some Thoughts on Working-Together

The need for information technology-mediated cooperation seems obvious. However, what is not obvious is what this means and what social demands such cooperation may imply. To explore this is the intention of the paper. As a first step the paper performs an etymological analysis of the words telecooperation and telecoordination. Such an analysis indicates that cooperation happens when people engage in the production of a work as if ‘one mind or body’, where their activities fuse together in a way that makes the suggestion of separation seem incomprehensible. In the work they do not merely aim to achieve an outcome, they also ‘insert’ themselves ‘in’ the work in a way that makes it a human achievement rather than a mere product – this is cooperation as working-together. With this notion of cooperation in mind the paper then proceeds to analyse the social conditions for cooperation as working-together. It shows, using the work of Wittgenstein, that language is fundamental to cooperation and the sharing of knowledge – not language as a system for the exchange of information but language as a medium for the co-creation of a local way of doing, a local language, to capture the local distinctions that make a particular local activity significant and meaningful to the participants. The paper then proceeds to question this strong notion of cooperation. It argues that most cooperative activities tend not to conform with such stringent demands. The paper suggests that a cooperative problem is best viewed as a situation in which ambiguity is accepted as a structural element of the interaction. From this perspective the paper suggests that hermeneutics may be a productive way to understand the creation of shared interpretative spaces that makes mediated cooperation possible. The paper concludes with some implications for mediated cooperative work.     

The Use of a Formalised Risk Model in NHS Information System Development

Information systems (IS) and technology are used extensively throughout the National Health Service (NHS), and the 1998 national information strategy, ‘Information for Health’, sets out how the NHS will be developing and implementing IS to support patient care within the next decade. This new IS initiative is set against a mixed record of success of IS projects in the NHS, with a number of high-profile failures. This paper highlights the need to consider the ‘organisational issues’ involved in systems implementation to avoid failures. It goes on to advocate the use of a process-oriented and organisation studies-based model for risk analysis and management for use in NHS IS projects. Two famous NHS case studies are used to validate the model. It is concluded that there is a real need in the NHS for tools to better control the inherent risks involved in IS development and implementation. Ultimately, the success of IS projects in the NHS is crucial if they want to best utilise clinical and patient information, with the overall aim of improving the efficiency and standard of the nation’s health care.     

The Context of Information Use in a Hospital as Simultaneous Similarity–Difference Relations

In the light of the developing discourse on the relative merits of ‘hard’ and ‘soft’ approaches to information systems development, we present a case study application of a methodology which attempts to dissolve such dualities. Personal Construct Psychology (PCP) offers, as a unity, the construing person who is both biology and culture. PCP argues that both the world and the person’s construct system are phenomenologically real and that the viability of any particular construct system depends only on its usefulness to the construing person. In this study, we used PCP to explore the organisational context of information use and distribution in a large hospital. We used repertory grids, a PCP technique, to elicit from 16 members of staff their personal construals of information from different sources in the hospital. The results highlight the relationship between meaningful information and meaningfully active relationships, a theme which we discuss in terms of the development of the hospital information system and in terms of the value of PCP in dissolving hard–soft dichotomies.     

Display Design of Process Systems Based on Functional Modelling

The prevalent way to present information in industrial computer displays is by using piping and instrumentation diagrams. Such interfaces have sometimes resulted in difficulties for operators because they are not sufficient to fulfil their needs. A systematic way that supports interface design therefore has to be considered. In the new design framework, two questions must be answered. Firstly, a modelling method is required to describe a process system. Such a modelling method can define the information content that must be displayed in interfaces. Secondly, how to communicate this information to operators efficiently must be considered. This will provide a basis for determining the visual forms that the information should take. This study discusses interface design of human–machine systems from these two points of view. Based on other scholars’ work, a comprehensive set of functional primitives is summarised as a basis to build a functional model of process systems. A library of geometrical presentations for these primitives is then developed. To support effective interface design, the concept of ‘functional macro’ is introduced and a way to map functional model to interface display is illustrated by applying several principles. To make our ideas clear, a central heating system is taken as an example and its functional model is constructed. Based on the functional model, the information to be displayed is determined. Several functional macros are then found in the model and their corresponding displays are constructed. Finally, by using the library of geometrical presentations for functional primitives and functional macros, the display hierarchy of the central heating system is developed. Reusability of functional primitives makes it possible to use the methodology to support interface design of different process systems.