Debbie Richards

A social software/Web 2.0 approach to collaborative knowledge engineering

Expert systems have traditionally captured the explicit knowledge of a single expert or source of expertise in order to automatically provide conclusions or classifications within a narrow problem domain. This is in stark contrast to social software which enables knowledge communities to share implicit knowledge of a more practical or experiential nature to inform individuals and groups to arrive at their own conclusions. Specialists are often needed to elicit and encode the knowledge in the case of expert systems, whereas one of the (claimed) hallmarks of social software and the Web 2.0 trend, such as Wikis and Blogs, is that everyone, anywhere can chose to contribute input. This openness in authoring and sharing content, however, tends to produce unstructured knowledge that is difficult to execute, reason over or automatically validate. This also poses limitations for its reuse. To facilitate the capture of knowledge-in-action which spans both explicit and tacit knowledge types, a knowledge engineering approach which offers Wiki-style collaboration is introduced. The approach extends a combined rule and case-based knowledge acquisition technique known as Multiple Classification Ripple Down Rules to allow multiple users to collaboratively view, define and refine a knowledge base over time and space.

Composing Web Services Using an Agent Factory

Web service composition can provide a value-chain between customers and suppliers. The increasing number of services, and thus possible combinations, demands the development of dynamic and automatic techniques for their composition. Current commercial solutions are limited and are primarily static and manual. Automation requires reasoning about (semantic descriptions of) the services. This paper describes our initial work which brings together agents, Web service and semantic Web technology. Our knowledge-based software engineering approach to the design of agents, known as the Agent Factory, is applied to the composition of Web services. Using semantic descriptions of Web services written in DAML-S, the design process in our Agent Factory derives a Web service configuration. This paper also includes some observations regarding our experiences with DAML-S, UDDI and WSDL for this purpose.

Designing Project-Based Courses with a Focus on Group Formation and Assessment

The value and the pitfalls of project and group work are well recognized. The principles and elements which apply to projects in general, apply to project-based courses. Thoughtful and detailed planning, understanding of the stakeholders and their needs, a good design, appropriate testing, monitoring and quality control and continual management can maximize the benefits and minimize the negatives. In this article we draw together the literature to consider key design choices of project-based courses considering: type, length, size, management, participants, and content with a particular focus on the composition of groups and the issues surrounding assessment.

Taking up the situated cognition challenge with ripple down rules

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.

Merging individual conceptual models of requirements

While it is acknowledged that system requirements will never be complete, incompleteness is often due to an inadequate process and methods for acquiring and tracking a representative set of requirements. Viewpoint development has been proposed to address these problems. We offer a viewpoint development approach that fits easily into the current practice of capturing requirements as use case descriptions. However, current practice does not support visualization of use case descriptions, the capture of multiple use case descriptions, the modeling of conflicts and the reconciliation of viewpoints. In our approach we apply techniques from natural language processing, term subsumption and set-theory to automatically convert the use case descriptions into a line diagram. The visualisation of use case descriptions is a natural addition to the object-oriented design of systems using the Unified Modelling Language where diagrams act as communication and validation devices. RECOCASE is a comprehensive methodology that includes use case description guidelines, a controlled language to support natural language translation, a requirements engineering process model and a tool to assist the specification and reconciliation of requirements. Our approach combines group and individual processes to minimise contradictions and missing information and maximise ownership of the requirements models. In this paper we describe each of the parts of our methodology following an example through each section.

Knowledge-based system explanation: the ripple-down rules alternative

Abstract. The ability to provide explanations has been seen as a key feature of expert systems (ES) typically not offered by other types ofcomputer systems. ES need to offer explanations because ofimprecise domains and the use ofheuristics. Verification is not enough. ES need to justify and be accountable. Explanation is seen as an important activity for knowledge-based systems as it satisfies the users need to decide whether to accept or reject a recommendation. In this paper we review explanation in first-generation and second-generation ES. An alternative is offered to the main approaches which uses multiple classification ripple-down rules and challenges even the goals of explanation. Instead of trying to give explanations which provide a meaningful line of reasoning and which are tailored to suit the individual it may be just as useful to provide the user with sufficient information and browsing tools to develop their own line of reasoning. The type of information that can assist understanding is the context in which the recommendation applies (which is provided through the display ofrelevant cases and exception rule history) and the ability to explore an abstraction hierarchy of the rules using formal concept analysis. An explanation tool kit aimed at putting the user in control is described and evaluated in this paper.

Design ontology in context — a situated cognition approach to conceptual modelling

Abstract If we take a situated view of cognition, human thought and action are inextricably connected and affected by the context. It is not just the external environment that will affect the context but that thinking itself modifies further action and context occurs at a conceptual level that exists within a social setting. Thus, a situated view of knowledge necessitates knowledge acquisition techniques which handle change. This is particularly true of design knowledge where the design will change as more experience is gained and the changing model will itself change the perception of a design while designing. The approach described in this paper is based on the view that knowledge is always evolving and the premise that it is not easy to capture or evaluate a conceptual model. The alternative offered is based on the combined use of cases, ripple-down rules (RDR), formal concept analysis (FCA) and the Activity/Space (A/S) ontology. Cases are design episodes and used to motivate the capture of rules in a simple user-driven manner. Cases ground the KBS in the real world and provide the context in which the knowledge applies. Rules are the indexes by which the cases are retrieved. Using FCA, we are able to build an abstraction hierarchy of the rules and cases. To facilitate comparison and validation we use A/S design ontology to acquire a consistently organised set of cases. This ontology provides a common structure and shared set of descriptive terms. The ease with which the knowledge is acquired and maintained using RDR, the use of a dynamic design ontology and the automatic generation of conceptual models using FCA allows for the continual evolution of the KBS in keeping with the notion that knowledge is continually evolving and ‘made-up’ to fit the situation.

The reuse of knowledge

The motivation for the work reported in this paper is the belief that not only is it beneficial to reuse knowledge but it is essential if we wish to build knowledge-based systems (KBS) that meet the needs of users. The focus of most KBS research is on complex modelling at the knowledge level which requires a knowledge engineer to act as the intermediary between the expert and the system. The type of reuse primarily considered is the reuse of ontologies or problem-solving methods so that improvements can be made in system quality and development time. However, there is little focus on the needs of users to access the knowledge in a variety of ways according to the individuals decision style or situation. The system described in this paper seeks to support the user in a number of different activities including knowledge acquisition, inferencing, maintenance, tutoring, critiquing, “what-if” analysis, explanation and modelling. The ability to ask different types of questions and to explore the knowledge in alternative ways is a different type of knowledge reuse. The knowledge acquisition and representation technique used as the foundation is known as ripple-down rules (RDR). To support the exploration activities, RDR have been combined with formal concept analysis which automatically generates an abstraction hierarchy from the low-level RDR assertions. The paper suggests that rapid and incremental KA together with retrospective modelling can be used to provide the user with a system that they can own, build and explore without the difficulties associated with capturing and validating the conceptual models of experts via the mediation of a knowledge engineer.

Knowledge Management and Acquisition for Smart Systems and Services

The last decade has seen an increasing interest in the use of 3D virtual environments for educational applications. However, very few studies investigated the influence of the learning context, such as class type and learning type, on learners’ academic performance. This paper studied the impact of class type (i.e. comprehensive or selective) classes, as well as learning type (i.e. guided or challenge and guided), on students’ level of usage of a Virtual Learning Environment (VLE) as well as on their academic performance. The results showed that, unlike class type, there is a significant difference between learners’ in their usage of the VLE. Moreover, the results showed that the levels of using a VLE significantly correlated with learners’ academic performance.

A Controlled Language to Assist Conversion of Use Case Descriptions into Concept Lattices

System requirements are often incomplete and riddled with contradictions leading to failed projects. Formal methods have been offered to minimise these problems. However the use of such techniques requires highly trained specialists and results in a process that users have little involvement with. We have developed a viewpoint development approach, known as RECOCASE, to capture requirements from multiple viewpoints directly from the users which are automatically modelled to identify and reconcile differences between stakeholder requirements. The requirements are captured as use case descriptions in natural language according to current popular practice in object-oriented system development. We use LinkGrammar on the use case sentences to output flat logical forms which we translate into crosstables and generate concept lattices using Formal Concept Analysis. To improve the output of our natural language process we have designed a controlled language to constrain the grammar and style. In this paper we introduce our natural language approach and describe and justify a controlled language we have developed to assist natural language translation.