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IJHCS Tables of Contents: 4041424344454647484950515253545556575859

International Journal of Human-Computer Studies 49

Editors:B. R. Gaines
Publisher:Academic Press
Standard No:ISSN 0020-7373; TA 167 A1 I5
Links:Table of Contents
  1. IJHCS 1998 Volume 49 Issue 1
  2. IJHCS 1998 Volume 49 Issue 2
  3. IJHCS 1998 Volume 49 Issue 3
  4. IJHCS 1998 Volume 49 Issue 4
  5. IJHCS 1998 Volume 49 Issue 5
  6. IJHCS 1998 Volume 49 Issue 6

IJHCS 1998 Volume 49 Issue 1

A Knowledge-Level Testing Method BIBA 1-20
  Corinne Haouche-Gingins; Jean Charlet
This paper aims at describing a testing method devoted to the study of knowledge-based systems (KBS) behaviour and results. Like any validation method, this method relies on specifications. Moreover, as the focus of the study is KBS behaviour, these specifications need to be expressed at high level. We distinguish between two kinds of specifications, system specifications and anomaly specifications, depending on the validation objectives. We adopt a knowledge-level perspective of validation since our first objective is to compare the KBS behaviour to expected behaviours that are a part of system specifications and described within a KADS conceptual model. In order to detect inconsistent results, we propose to add some kind of validation knowledge to the domain level knowledge. This method is illustrated by the validation of a prototype for natural language understanding.
Some Advantages of Video Conferencing over High-Quality Audio Conferencing: Fluency and Awareness of Attentional Focus BIBA 21-58
  Owen Daly-Jones; Andrew Monk; Leon Watts
There are many commercial systems capable of transmitting a video image of parties in a conversation over a digital network. Typically, these have been used to provide facial images of the participants. Experimental evidence for the advantages of such a capability has been hard to find. This paper describes two experiments that demonstrate significant advantages for video conferencing over audio-only conferencing, in the context of a negotiation task using electronically shared data. In the video condition there was a large, high-quality image of the head and upper torso of the participant(s) at the other end of the link and high-quality sound. For the audio-alone condition the sound was the same but there was no video image. The criteria by which these two communication conditions were compared were not the conventional measures of task outcome. Rather, measures relating to conversational fluency and interpersonal awareness were applied. In each of the two experiments, participants completed the same task with data presented by a shared editor. In Experiment 1, they worked in pairs and in Experiment 2 they worked at quartets with two people at each end of the link. Fluency was assessed from transcripts in terms of length of utterance, overlapping speech and explicit questions. Only the latter measure discriminated between the two communication conditions in both experiments. The other measures showed significant effects in Experiment 2 but not in Experiment 1. Given this pattern of results it is concluded that video can result in more fluent conversation, particularly where there are more than two discussants. However, in the case of dyadic conversation auditory cues to turn taking, etc., would seem to suffice. In both experiments there was a large and significant effect on interpersonal awareness as assessed by ratings of the illusion of presence, and most clearly, awareness of the attentional focus of the remote partner (s). In Experiment 2, the ratings for the remote partners were similar to those for the co-located discussants, demonstrating the effectiveness of the video link with regard to these subjective scales.
Apparency of Contingencies in Single Panel and Pull-Down Menus BIBA 59-78
  Diane Lindwarm Alonso; Kent L. Norman
In menu interfaces what is shown is not always what is available and how to make it available is not always apparent. This is the problem when items on a single panel or a pull-down menu are disabled. Generally, the underlying structure of an interface is hidden from the user's view, and it may be quite difficult for the user to figure out the sequence of selections to enable the desired options. Users high in spatial visualization ability (SVA) are often quick to learn the contingencies underlying the menus and are not severely hindered by this problem; however, low SVA users generally experience substantial difficulty in visualizing these contingencies and often get lost. We conducted two experiments to determine whether revealing hidden contingencies through visual cues would facilitate the performance of low SVA users on a computerized path-finding task. In general, it was found that increasing interface apparency benefits all users, but particularly those with low SVA. Specifically, methods of displaying single paths in a menu hierarchy using either lines or color coding were the most effective.
Are Computers Scapegoats? Attributions of Responsibility in Human-Computer Interaction BIBA 79-94
  Youngme Moon; Clifford Nass
This study investigated how people make attributions of responsibility when interacting with computers. In particular, two questions were addressed: under what circumstances will users blame computers for failed outcomes? And under what circumstances will users credit computers for successful outcomes? The first prediction was that similarity between a user's personality and a computer's personality would reduce the tendency for users to exhibit a "self-serving bias" in assigning responsibility for outcomes in human-computer interaction. The second prediction was that greater user control would lead to more internal attributions, regardless of outcome. A 2x2x2 balanced, between-subjects experiment (N=80) was conducted. Results strongly supported the predictions: when the outcome was negative, participants working with a similar computer were less likely to blame the computer and more likely to blame themselves, compared with participants working with a dissimilar computer. When the outcome was positive, participants working with a similar computer were more likely to credit the computer and less likely to take the credit themselves, compared with participants working with a dissimilar computer. In addition, when users were given more control over outcomes, they tended to make more internal attributions, regardless of whether the outcome was positive or negative.

IJHCS 1998 Volume 49 Issue 2

Formal Description and Evaluation of User-Adapted Interfaces BIBA 95-120
  Fiorella de Rosis; Sebastiano Pizzutilo; Berardina de Carolis
This paper describes a visual formalism and a tool to support design and evaluation of human-computer interaction in context-customized systems. The formalism is called XDM (for "context-sensitive dialogue modelling") and combines extended Petri nets with Card, Moran and Newell's KLM operators theory to describe static and dynamic aspects of interaction in every context in which the system should operate, and to make evaluations of interface correctness and usability easier or automatic. The method was developed in the scope of a European Community Project to iteratively prototype a knowledge-based medical system. It has been subsequently employed in several research projects and in teaching activities.
Knowledge Modeling Directed by Situation-Specific Models BIBA 121-157
  Michel Benaroch
Clancey (1992) proposed the model-construction framework as a way to explain the reasoning of knowledge-based systems (KBSs), based on his realization that all KBSs construct implicit or explicit situation-specific models (SSMs). An SSM is a rational argument that explains the solution produced for a specific problem situation pertaining to a target application task (e.g. SSMs constructed for typical diagnosis tasks are causal arguments having the structure of a proof). From a knowledge engineering perspective it makes sense that the notion of an SSM should play a major role in the modeling of tasks. Motivated by this view, we present a structured knowledge modeling methodology called SSM-directed knowledge modeling (SSM-DKM). In SSM-DKM, an SSM is a central structure that drives the entire modeling endeavor. In light of this fact, we explain how SSM-DKM supports three main stages in the knowledge engineering process-conceptualization, formalization and validation and instantiation-and illustrate the application of SSM-DKM to a medical diagnosis task. The knowledge model that SSM-DKM produces for a target application task has two appealing traits. First, the model embodies explicit knowledge about the ontology of SSMs that the task entails creating as solutions, thus enabling the construction of a KBS that makes these SSMs explicit. Second, the model captures strategic (or problem-solving) knowledge in declarative terms pertaining to the ontology of SSMs created for the task. Both these beneficial traits have been illustrated in the context of ACE-SSM, a KBS architecture that constructs explicit SSMs (Benaroch, 1998).
Transparent Fuzzy Modelling BIBA 159-179
  M. Setnes; R. Babuska; H. B. Verbruggen
One of the objectives of machine learning is to enable intelligent systems to acquire knowledge in a highly automated manner. In systems modelling and control engineering, fuzzy systems have shown to be highly suitable for the modelling of complex and uncertain systems. Recently, the interest in fuzzy systems has shifted from the seminal ideas about modelling the process or the behaviour of operators by knowledge acquisition towards a data-driven approach. Reasons to choose fuzzy systems instead of modelling techniques such as neural networks, radial basis functions, genetic algorithms or splines, are mainly the possibility of integrating logical information processing with the attractive mathematical properties of general function approximators. Furthermore, the rule-based structure of fuzzy systems makes analysis easier. The fuzzy sets in the rules represent linguistic qualitative terms that approximate the human-like way of information quantization. However, many of the data-driven fuzzy modelling algorithms that have been developed, aim at good numerical approximation and pay little attention to the semantical properties of the resulting rule base. In this article, we briefly discuss different approaches to data-intensive fuzzy modelling reported in the literature. Next, we present a data-driven approach to fuzzy modelling that provides the user with both accurate and transparent rule bases. The method has two main steps: data exploration by means of fuzzy clustering and fuzzy set aggregation by means of similarity analysis. First, fuzzy relations are identified in the product space of the system's variables and are described by means of fuzzy production rules. Compatible fuzzy concepts defined for the individual variables are then identified and aggregated to produce generalizing concepts, giving a comprehensible rule base with increased semantic properties. The transparent fuzzy modelling approach is demonstrated on a real world problem concerning the modelling of algae growth in lakes.
A Relational Model of Cognitive Maps BIBA 181-200
  B. Chaib-Draa; J. Desharnais
A useful tool for causal reasoning is the language of cognitive maps developed by political scientists to analyse, predict and understand decisions. Although, this language is based on simple inference rules and its semantics is ad hoc, it has many attractive aspects and has been found useful in many applications: administrative sciences, game theory, information analysis, popular political developments, electrical circuits analysis, cooperative man-machines, distributed group-decision support and adaptation and learning, etc. In this paper, we show how cognitive maps can be viewed in the context of relation algebra, and how this algebra provides a semantic foundation that helps to develop a computational tool using the language of cognitive maps.

IJHCS 1998 Volume 49 Issue 3

Side-by-Side Collaboration: A Case Study BIBA 201-222
  Nick V. Flor
I analyse the discourse and cross-workspace information movement between two collaborators working side by side on a maintenance task. The analysis revealed four mutually constraining representations: task, system structure, modifications and system behavior. Side-by-side collaborators push or pull information across workspaces in an attempt to ground common representations of these four structures. Although the representations collaborators actually create vary with the type of collaborative endeavor, pushing and pulling information across workspaces is a general collaborative activity. I end by discussing ways in which the push/pull conception of collaboration can be used to inform the design of effective remote collaboration tools.
A Formal and Structured Approach to the Use of Task Analysis in Accident Modelling BIBA 223-244
  R. M. Botting; C. W. Johnson
Recent work (Telford & Johnson, 1996; Johnson, 1997), involving the application of formal notations to analyse accident reports has shown that the quality of these accident reports is poor, so much so that their conclusions can be misleading. The proposed solution has been to use formal notations in combination with traditional analysis to produce a report, the conclusions of which can be verified by formal reasoning. However, there are weaknesses with the formal notations used up until now. Firstly, they have not allowed the representation of all aspects of an accident or incident. For example, human factors have either not been represented or not clearly delineated from system factors. In particular, there has not been an attempt to provide a task analysis of the incident. Secondly, the notations used do not easily facilitate the system engineering concepts of modularity, encapsulation or scalability. In consequence, it is difficult to model different aspects of an accident, compose these different aspects to build up the model or make changes to parts of the model without affecting the rest of the model. The purpose of this paper is to demonstrate how a formal object-oriented specification language can be used to provide the benefits offered by an engineering approach and in particular, by using this approach, how a task analysis model can be constructed. The task analysis incorporates Hollnagel's (1993) classification of erroneous actions, so that scenarios, deriving from human error, can be reasoned about. An air accident investigation report, issued by the UK Civil Aviation Authority, is used as a case study.
Training Software Engineers in a Novel Usability Evaluation Technique BIBA 245-279
  Ann E. Blandford; Simon J. Buckingham Shum; Richard M. Young
Novel approaches to designing or analysing systems only become useful when they are usable by practitioners in the field, and not just by their originators. Design techniques often fail to make the transition from research to practice because insufficient attention is paid to understanding and communicating the skills required to use them. This paper reports on work to train software engineering students to use a user-centred language for describing and analysing interface designs called the "Programmable User Model Instruction Language", or IL. Various types of data, including video, students' IL descriptions and brief usability reports were collected during training, and subsequently analysed. These show that after 6 h of training, students have a good grasp of the syntax of the notation, and start using notational affordances to support their reasoning, but that their reasoning is still limited by a poor grasp of the underlying cognitive theory. A comparison of the analyses of trainees with those of experts provides a means of developing a better understanding of the nature of expertise in this area-as comprising an understanding of the syntax and the surface semantics of the notation, the underlying cognitive theory, the method of conducting an analysis and the implications of the analysis for design.
Problem Domain Categories in Requirements Engineering BIBA 281-304
  N. A. M. Maiden; M. Hare
Requirements engineering is the complex technical, social and cognitive process which produces requirements for a software-intensive system. However, little is understood about the problem domains for which these software-intensive systems are developed. Card sorting was used to determine mental categories of problem domains to inform design of a library of semi-formal, reusable object system models. Card sorting is a knowledge elicitation technique effective for eliciting mental categories from subjects who sort concepts such as objects or problems into categories. In NATURE, we anticipate better reuse if object system models in NATURE's database correspond to natural mental categories elicited using card sorting from experienced software engineers. Results led to some revision of the structure and contents of several models and how these models might be retrieved and used.

IJHCS 1998 Volume 49 Issue 4

Editorial: Problem-Solving Methods BIB 305-313
  V. Richard Benjamins; Dieter Fensel
A Competence Theory Approach to Problem Solving Method Construction BIBA 315-338
  B. J. Wielinga; J. M. Akkermans; A. Th. Schreiber
This paper presents a theory of the construction process of problem-solving methods (PSMs) on the basis of the competence theory approach. This approach describes the refinement process of an initial, abstract formalization of the required competence of a PSM, towards an operational version of the PSM. Three major steps in this process are identified: specification of the required competence theory, refinement of the theory into a form that fits a PSM paradigm and the operationalization of the theory into a form that is close to an executable specification. As an example, the ontological commitments and assumptions underlying some problem-solving methods for classification problems are investigated and their operational forms are presented.
Inverse Verification of Problem-Solving Methods BIBA 339-361
  Dieter Fensel; Arno Schonegge
Context dependency of knowledge models brings with it several problems: the unreliability of knowledge-based systems, maintenance costs and limitations on sharing and reuse. Problem-solving methods are knowledge models of the reasoning process of knowledge-based systems. In this paper, we present a method called inverse verification to deal with the context dependency of problem-solving methods. Inverse verification investigates the context dependency of a method by making underlying assumptions explicit. It uses failed proof attempts as a search method for assumptions and an analysis of these failures for constructing and refining assumptions.
Construction of Problem-Solving Methods as Parametric Design BIBA 363-389
  A. Ten Teije; F. van Harmelen; A. Th. Schreiber; B. J. Wielinga
The knowledge-engineering literature contains a number of approaches for constructing or selecting problem solvers. Some of these approaches are based on indexing and selecting a problem solver from a library, others are based on a knowledge acquisition process, or are based on search-strategies. None of these approaches sees constructing a problem solver as a configuration task that could be solved with an appropriate configuration method. We introduce a representation of the functionality of problem-solving methods that allows us to view the construction of problem solvers as a configuration problem, and specifically as a parametric design problem. From the available methods for parametric design, we use propose-critique-modify for the automated configuration of problem-solving methods. We illustrate this approach by a scenario in a small car domain example.
The CommonKADS Library in Perspective BIBA 391-416
  Andre Valente; Joost Breuker; Walter van de Velde
The CommonKADS Expertise Modeling Library is the result of work that started as a further development of the KADS Library of interpretation models (Breuker et al., 1987). It incorporates new views and experiences of the knowledge acquisition community on the reuse of problem-solving components, in particular problem-solving methods and their assumptions on domain knowledge. Its design allows to store and index an extensible set of modeling components of different levels of granularity, as well as generic (partial) models of expertise and even reusable modeling steps. Further, its contents were significantly expanded, in what is probably the largest library of problem solving methods presently. In this article, we explain the rationale of the design of the CommonKADS library, the mechanisms defined to index the elements it stores, and the Library contents. An example of the use of a part of the Library concerned with problem-solving methods for assessment tasks is presented. The Library is not a finished product: not only because still many contents may need further verification and validation, but also because the Library is intended to accumulate and share practical experiences and advice on the process of modeling for actual applications. These and other shortcomings and lessons are discussed.
Some Principles for Libraries of Task Decomposition Methods BIBA 417-435
  Klas Orsvarn
Chandrasekaran and Steels proposed several years ago that libraries of reusable problem-solving methods, for use in model-driven knowledge acquisition, should be organized as hierarchies of task decomposition methods, rather than as collections of complete methods. Using such a library, a complete problem-solving method can be generated for an application, on the basis of selection criteria. This paper proposes a set of general principles which libraries of task decomposition methods can be evaluated against, concerning method correctness, specialization of selection criteria, and method generality. The objective of the principles is to facilitate the process of using a library of task decomposition methods in application modelling, by reducing the need to make adaptations of complete methods generated with the library. The principles were motivated by difficulties encountered in a case-study of modelling a specific diagnosis application using one of the most comprehensive libraries of task decomposition methods-Benjamins' library of diagnosis methods. It is shown how those difficulties could have been avoided, if Benjamins' library had been explicitly evaluated against the proposed principles.
A Library of Problem-Solving Components Based on the Integration of the Search Paradigm with Task and Method Ontologies BIBA 437-470
  Enrico Motta; Zdenek Zdrahal
In this paper we investigate the reuse of tasks and problem-solving methods and we propose a model of how to organize a library of reusable components for knowledge-based systems. In our approach, we first describe a class of problems by means of a task ontology. Then we instantiate a generic model of problem solving as search in terms of the concepts in the task ontology, to derive a task-specific, but method-independent, problem-solving model. Individual problem-solving methods can then be (re-)constructed from the generic problem-solving model through a process of ontology/method specialization and configuration. The resulting library of reusable components enjoys a clear theoretical basis and has been tested successfully on a number of applications. In the paper, we illustrate the approach in the area of parametric design.
Supporting Organization and Use of Problem-Solving Methods Libraries by a Formal Approach BIBA 471-495
  Christine Pierret-Golbreich
Different libraries of problem-solving methods have been described in the past few years. But they have mostly been defined at an informal or operational level and rarely at the formal level. Since their components lack a clear definition and rigorous structuration, it is difficult to ensure that a method selected from a library is correctly reused in the development of an application. This is the reason why we have chosen a formal approach to support problem-solving methods libraries organisation and use. Our approach is based on algebraic specifications. Our first contribution presents how such formal techniques can provide reusable PSMs with a precise and unambiguous semantics and with a mathematically well-defined hierarchical structuration. Second, we show how reusing and adapting such PSMs to develop particular applications can be rigorously formalized. A library fragment of assignment methods is used to illustrate how to structure a PSM library. Sisyphus I example is used to describe how to derive a formal specification of an application by reusing components of this library. The paper focuses on the competence of PSMs regardless of their dynamic aspects.
Generalized Directive Models: Integrating Model Development and Knowledge Acquisition BIBA 497-522
  Kieron O'Hara; Nigel Shadbolt; Gertjan van Heijst
The Generalized directive model (GDM) methodology for knowledge acquisition is introduced. For GDMs to work two assumptions are required: that knowledge acquisition has a cyclic structure interleaving episodes of model development and domain KA, and that increased specification of one part of a model does not affect other parts. The use of GDMs is illustrated with a real-world example from an Airborne Early Warning system, showing the development of a model for one sub-task using the PC-based GDM tool from the commercial workbench PC-PACK. There is also a small example of a GDM analysis extending an already existing model. Finally, GDMs are compared with the decompositional CommonKADS library.
Reuse, CORBA, and Knowledge-Based Systems BIBA 523-546
  John H. Gennari; Heyning Cheng; Russ B. Altman; Mark A. Musen
By applying recent advances in the standards for distributed computing, we have developed an architecture for a CORBA implementation of a library of platform-independent, sharable problem-solving methods and knowledge bases. The aim of this library is to allow developers to reuse these components across different tasks and domains. Reuse should be cost-effective; therefore, the library will include standard problem-solving methods whose semantics are well understood and are described with a language for stating the requirements and capabilities of a component. In addition, when a developer needs to adapt a component to a new task, the adaptation costs should be minimal. Thus, we advocate the use of separate mediating components that isolate these adaptations from the original component. We demonstrate our approach with an example: an implementation of a problem-solving method, a knowledge-base server, and mediating components that adapt the method to different knowledge bases and tasks.
Preserving Conceptual Structures in Design and Implementation of Industrial KBSs BIBA 547-575
  Piet-Hein Speel; Manfred Aben
Applying the best available knowledge at the right place and the right time is crucial for industries like Unilever. As one approach to careful knowledge management, we are developing knowledge-based systems (KBSs) to capture and exploit key knowledge. For this purpose, we have adopted and tailored the CommonKADS method as a standard to develop KBSs. In Speel and Aben (1997), we have reported our positive experiences in reusing problem-solving methods (PSMs). In this paper, we focus on the feasibility of another important technique called structure-preserving design and implementation (SPD).
   In the literature it is claimed that SPD leads to many benefits including improved maintenance and reuse of program code. In this paper, we discuss our experiences in applying SPD in an extensive case study. We have tested the validity of the scientifically claimed pros and cons during the development of four industrial KBSs. For these off-line diagnosis and assessment applications, we found that the SPD approach is feasible and improves maintainability, encourages reuse on all levels, contributes to improved understandability, documentation and explanation and promotes systematization. In addition, the off-line KBSs do not demonstrate any serious performance problems.
A Structure of Problem-Solving Methods for Real-Time Decision Support in Traffic Control BIBA 577-600
  Martin Molina; Josefa Hernandez; Jose Cuena
This article describes a knowledge-based application in the domain of road traffic management that we have developed following a knowledge modelling approach and the notion of problem-solving method. The article presents first a domain-independent model for a real-time decision support as a structured collection of problem solving methods. Then, it is described how this general model is used to develop an operational version for the domain of traffic management. For this purpose, a particular knowledge modelling tool, called Knowledge Structure Manager (KSM) was applied. Finally, the article shows an application developed for a traffic network of the city of Madrid and it is compared with a second application developed for a different traffic area of the city of Barcelona.
Domain-Oriented Library of Scheduling Methods: Design Principle and Real-Life Application BIBA 601-626
  Masahiro Hori; Taketoshi Yoshida
This paper presents a library of problem-solving methods dedicated to production scheduling, and reports our experience in applying the library to the development of a real-life system. The library consists of three loosely coupled sub-systems: a manufacturing domain model, scheduling methods and graphical user interfaces. The domain model provides fundamental concepts to be employed by the other two sub-systems. In particular, the relationship between scheduling methods as articulated in terms of the structural relations among concepts in the domain model. Application systems developed with the library can be extended by modifying the configurations of the sub-systems and elaborating the concepts in each sub-system. The reusability of the library is investigated in terms of the ratio of code reuse in a real case. Finally, we compare our approach with related studies, and draw implications for designing domain-oriented libraries of problem-solving methods, taking account of the transition of knowledge-modelling perspectives.
Knowledge Reuse among Diagnostic Problem-Solving Methods in the Shell-Kit D3 BIBA 627-649
  Frank Puppe
While diagnostic problem solving is in principle well understood, building and maintaining systems in large domains cost effectively is an open issue. Various methods have different advantages and disadvantages making their integration attractive. When switching from one method to another in an integrated system, as much knowledge as possible should be reused. We present an inference structure for diagnostic problem solving optimized with respect to knowledge reuse among methods motivated by experience from large knowledge bases built in medical, technical and other diagnostic domains.

IJHCS 1998 Volume 49 Issue 5

Making the Most of Ecological Interface Design: The Role of Self-Explanation BIBA 651-674
  Dianne E. Howie; Kim J. Vicente
Ecological interface design (EID) is a candidate framework for designing interfaces for complex sociotechnical systems. Interfaces based on EID have been shown to lead to better performance than traditional interfaces, but not all participants benefit equally. Thus, it is important to identify ways of raising the performance of all participants using an EID interface. The purpose of this article is to determine whether encouraging participants to engage in self-explanations (i.e. reasoning aloud) can help them "make the most" of EID. An experiment was conducted using DURESS II, an interactive, thermal-hydraulic process control microworld with an interface designed according to the principles of EID. During this one-month study, participants controlled DURESS II under normal and fault conditions on a quasi-daily basis. Two experimental groups occasionally watched a replay of their own performance immediately after completing a trial, while the control group did not. In addition, the self-explanation (SE) group was instructed to explain aloud the reasons for their control actions while watching the replay. The replay group simple watched their trials again with no verbal explanation. The SE participants were divided into "good" and "poor" groups according to several performance criteria. An analysis of the protocols produced during self-explanation revealed that "good" SE participants showed more signs of self-explanation in their protocols than did the "poor" SE participants. There were no substantial differences between the SE, replay and control groups for normal trials. However, the SE participants did have the best overall performance on fault trials, suggesting that self-explanation can help operators make the most of EID.
Formal Architectural Abstractions for Interactive Software BIBA 675-715
  Panos Markopoulos; Peter Johnson; Jon Rowson
This paper discusses formal interactor models, a class of abstractions for modelling user interface software that incorporate elements of its structure. The abstraction-display-controller (ADC) interactor model is one such abstraction which draws on research into user interface architectures and on earlier approaches to the formal specification of user interfaces. The ADC interactor model is specified formally using the LOTOS specification language. As a concept and as a representation scheme the ADC interactor model applies both to the user interface as a whole and also to its components. This property is preserved when interactors are combined to describe more complex entities or, conversely, when an interactor is decomposed into smaller-scale interactors. The paper includes a discussion of the ADC model and its use for the verification of user-interface software.
Modelling Self-Confidence in Users of a Computer-Based System Showing Unrepresentative Design BIBA 717-742
  P. Briggs; B. Burford; C. Dracup
While a great deal of research has demonstrated that users' self-efficacy beliefs have a major impact upon both their attitudes to technology and their performance, a related construct, self-confidence, has been largely ignored within the domain of human-computer interaction. This is surprising given the vast literature on the calibration of confidence which can be found within the judgment and decision literature. In this study, 60 participants were asked to complete a novel computer-based task, and to provide measures of self-confidence in terms of their anticipated performance at each stage of the task. Users' confidence judgements showed sensitivity to their rate of improvement on the task, but were poorly calibrated with actual performance at each stage. Furthermore, confidence judgements were insensitive to the complexity of the individual task components, even though these different components led to very different levels of performance. The style of computer interface was also found to affect anticipated performance independently of actual performance. The ability of existing models of confidence judgement to deal with these data is discussed.
Formulating the Cognitive Design Problem of Air Traffic Management BIBA 743-766
  John Dowell
Evolutionary approaches to cognitive design in the air traffic management (ATM) system can be attributed with a history of delayed developments. This issue is well illustrated in the case of the flight progress strip where attempts to design a computer-based system to replace the paper strip have consistently been met with rejection. An alternative approach to cognitive design of air traffic management is needed and this paper proposes an approach centred on the formulation of cognitive design problems. The paper gives an account of how a cognitive design problem was formulated for a simulated ATM task performed by controller subjects in the laboratory. The problem is formulated in terms of two complimentary models. First, a model of the ATM domain describes the cognitive task environment of managing the simulated air traffic. Second, a model of the ATM worksystem describes the abstracted cognitive behaviours of the controllers and their tools in performing the traffic management task. Taken together, the models provide a statement of worksystem performance, and express the cognitive design problem for the simulated system. The use of the problem formulation in supporting cognitive design, including the design of computer-based flight strips, is discussed.

IJHCS 1998 Volume 49 Issue 6

Editorial: The Challenge of Situated Cognition for Symbolic Knowledge-Based Systems BIB 767-769
  Tim Menzies; William J. Clancey
Situated Learning using Descriptive Models BIBA 771-796
  Tariq M. Khan; John E. M. Mitchell; K. E. Brown; R. Roy Leitch
A perspective on situated learning is presented which proposes that navigating within a space of many descriptive models overcomes limitations inherent in mono-model approaches to learning contextualized knowledge. The situationist view may be interpreted as drawing attention to neglected aspects of knowledge such as non-verbal, tacit, sub-conscious, metacognitive and affective. Although these elements have evaded adequate modelling for the purpose of simulating human behaviour, they can be "attended to" from descriptions to support human behaviour-however, the utility of a representation depends on the kind of knowledge so described. Different viewpoints of a situation, such as the learner's and a professional's, can be described with different models, which differ in fundamental dimensions. These facilitate communication of viewpoints between learners and professional members of the community, so that though negotiation a synthesis emerges which retains critical aspects of both view points-this is learning. Other interactions between viewpoints develop other affective and metacognitive skills. The many elements of situated action and knowledge are discussed and then a methodology for supporting situated learning with multiple descriptive models is presented. A situated learning environment is present, founded on multiple models, which demonstrates that switching between models is a metalevel process for changing viewpoints and this is the basis of integrating learners into new communities of practice. Learning problem solving, developing identities and refining roles are all introduced and consolidated by an example using multiple models to develop affective conciliation skills. The examples given illustrate how part of a professional's knowledge can be used by a learner for one particular approach to learning. However, the representation of the professional, using this multiple models approach, would include informal knowledge from the community of practice as well as formal knowledge. This combination of different knowledge types allows a variety of learning situations to be accommodated.
An Ontology for Framing BIBA 797-830
  John O'Neill
Framing is the process of conceiving new situations which may change an organization's behaviour. These situations are often "wicked" in nature, and may be defined by reinterpreting the meaning of an organization's intent. A real-world case study is used to illustrate the framing process and derive an ontology for framing. A computer tool called FRAMER is described that implements the framing ontology and supports the framing process. A key feature of FRAMER is the ability for people to adapt and redefine knowledge representations as they articulate new theories, and extend existing theories, about an organization.
Brahms: Simulating Practice for Work Systems Design BIBA 831-865
  William J. Clancey; Patricia Sachs; Maarten Sierhuis; Ron van Hoof
A continuing problem in business today is the design of human-computer systems that respect how work actually gets done. The overarching context of work consists of activities, which people conceive as ways of organizing their daily life and especially their interactions with each other. Activities include reading mail, going to workshops, meeting with colleagues over lunch, answering phone calls, and so on. Brahms is a multiagent simulation tool for modeling the activities of groups in different locations and the physical environment consisting of objects and documents, including especially computer systems. A Brahms model of work practice reveals circumstantial, interactional influences on how work actually gets done, especially how people involve each other in their work. In particular, a model of practice reveals how people accomplish a collaboration through multiple and alternative means of communication, such as meetings, computer tools, and written documents. Choices of what and how to communicate are dependent upon social beliefs and behaviors-what people know about each other's activities, intentions, and capabilities and their understanding of the norms of the group. As a result, Brahms models can help human-computer system designers to understand how tasks and information actually flow between people and machines, what work is required to synchronize individual contributions, and how tools hinder or help this process. In particular, workflow diagrams generated by Brahms are the emergent product of local interactions between agents and representational artifacts, not pre-ordained, end-to-end paths built in by a modeler. We developed Brahms as a tool to support the design of work by illuminating how formal flow descriptions relate to the social systems of work; we accomplish this by incorporating multiple views-relating people, information, systems, and geography-in one tool. Applications of Brahms could also include system requirements analysis, instruction, implementing software agents, and a workbench for relating cognitive and social theories of human behavior.
Towards Situated Knowledge Acquisition BIBA 867-893
  Tim Menzies
Situated cognition is not a mere philosophical concern: it has pragmatic implications for current practice in knowledge acquisition. Tools must move from being design-focused to being maintenance-focused. Reuse-based approaches (e.g. using problem-solving methods) will fail unless the reused descriptions can be extensively modified to suit the new situation. Knowledge engineers must model not only descriptions of expert knowledge, but also the environment in which a knowledge base will perform. Descriptions of knowledge must be constantly re-evaluated. This re-evaluation process has implications for assessing representations.
Taking Up the Situated Cognition Challenge with Ripple Down Rules BIBA 895-926
  Debbie Richards; Paul Compton
Situated cognition poses a challenge that requires a paradigm shift in the way we build symbolic knowledge-based systems. Current approaches require complex analysis and modelling and the intervention of a knowledge engineer. They rely on building knowledge-level models which often result in static models that suffer from the frame of reference problem. This approach has also resulted in an emphasis on knowledge elicitation rather than user requirements elicitation. The situated nature of knowledge necessitates a review of how we build, maintain and validate knowledge-based systems. We need systems that are flexible, intuitive and that interact directly with the end-user. We need systems that are designed with maintenance in mind, allowing incremental change and on-line validation. This will require a technique that captures knowledge in context and assists the user to distinguish between contexts. We take up this challenge with a knowledge acquisition and representation method known as Ripple-down Rules. Context in Ripple-down Rules is handled by its exception structure and the storing of the case that prompted a rule to be added. A rule is added as a refinement to an incorrect rule by assigning the correct conclusion and picking the salient features in the case that differentiate the current case from the case associated with the wrong conclusion. Thus, knowledge acquisition and maintenance are simple tasks, designed to be performed incrementally while the system is in use. Knowledge acquisition, maintenance and inferencing are offered in modes that can be performed reflexively without a knowledge engineer. We further describe the addition of modelling tools to assist the user to reflect on their knowledge for such purposes as critiquing, explanation, "what-if" analysis and tutoring. Our aim is to provide a system that lets the user choose the mode of interaction and view of the knowledge according to the situation in which they find themselves and their own personal preferences.
Constructive Cognition in a Situated Background BIBA 927-933
  Alain T. Rappaport
In the present commentary, situatedness, or context dependence is seen as a general principle of human knowledge and activities, and cognition is a constructive process taking place in a situated background. We contend that a "constructive cognition" model would encompass situatedness, regardless of the paradigm in use for its implementation and that there is no fundamental incompatibility between situatedness and the use of either implicit or descriptive expressions of knowledge. We present some evidence from cognitive neuroscience in favor of this constructive paradigm. The same evidence should, in turn, influence the design of useful technologies to support and extend cognitive activities.