Alexandra Poulovassilis

Learning as immersive experiences: Using the four-dimensional framework for designing and evaluating immersive learning experiences in a virtual world

Traditional approaches to learning have often focused upon knowledge transfer strategies that have centred on textually-based engagements with learners, and dialogic methods of interaction with tutors. The use of virtual worlds, with text-based, voice-based and a feeling of ‘presence’ naturally is allowing for more complex social interactions and designed learning experiences and role plays, as well as encouraging learner empowerment through increased interactivity. To unpick these complex social interactions and more interactive designed experiences, this paper considers the use of virtual worlds in relation to structured learning activities for college and lifelong learners. This consideration necessarily has implications upon learning theories adopted and practices taken up, with real implications for tutors and learners alike. Alongside this is the notion of learning as an ongoing set of processes mediated via social interactions and experiential learning circumstances within designed virtual and hybrid spaces. This implies the need for new methodologies for evaluating the efficacy, benefits and challenges of learning in these new ways. Towards this aim, this paper proposes an evaluation methodology for supporting the development of specified learning activities in virtual worlds, based upon inductive methods and augmented by the four-dimensional framework reported in a previous study. The study undertaken aimed to test the efficacy of the proposed evaluation methodology and framework, and to evaluate the broader uses of a virtual world for supporting lifelong learners specifically in their educational choices and career decisions. The paper presents the findings of the study and considers that virtual worlds are reorganising significantly how we relate to the design and delivery of learning. This is opening up a transition in learning predicated upon the notion of learning design through the lens of ‘immersive learning experiences’ rather than sets of knowledge to be transferred between tutor and learner. The challenges that remain for tutors rest with the design and delivery of these activities and experiences. The approach advocated here builds upon an incremental testing and evaluation of virtual world learning experiences.

An event-condition-action language for XML

XML repositories are now a widespread means for storing and exchanging information on the Web. As these repositories become increasingly used in dynamic applications such as e-commerce, there is a rapidly growing need for a mechanism to incorporate reactive functionality in an XML setting. Event-condition-action (ECA) rules are a technology from active databases and are a natural method for supporting suchfunctionality. ECA rules can be used for activities such as automatically enforcing document constraints, maintaining repository statistics, and facilitating publish/subscribe applications. An important question associated with the use of a ECA rules is how to statically predict their run-time behaviour. In this paper, we define a language for ECA rules on XML repositories. We then investigate methods for analysing the behaviour of a set of ECA rules, a task which has added complexity in this XML setting compared with conventional active databases.

Event-condition-action rule languages for the semantic web

The Semantic Web is based on XML and RDF as its fundamental standards for exchanging and storing information on the World Wide Web. Event-condition-action (ECA) rules are a natural candidate for supporting reactive functionality on XML or RDF repositories. In this paper we describe a language for ECA rules on XML and a prototype implementation of this language. We also discuss some preliminary ideas regarding a language for ECA rules operating on a graph/triple representation of RDF, and we describe the architecture of a distributed deployment of such RDF ECA rules.

Data integration by bi-directional schema transformation rules

We describe a new approach to data integration which subsumes the previous approaches of local as view (LAV) and global as view (GAV). Our method, which we term both as view (BAV), is based on the use of reversible schema transformation sequences. We show how LAV and GAV view definitions can be fully derived from BAV schema transformation sequences, and how BAV transformation sequences may be partially derived from LAV or GAV view definitions. We also show how BAV supports the evolution of both global and local schemas, and we discuss ongoing implementation of the BAV approach within the AutoMed project.

Schema Evolution in Heterogeneous Database Architectures, A Schema Transformation Approach

This paper presents a new approach to schema evolution, which combines the activities of schema integration and schema evolution into one framework. In previous work we have developed a general framework to support schema transformation and integration in heterogeneous database architectures. Here we show how this framework also readily supports evolution of source schemas, allowing the global schema and the query translation pathways to be easily repaired, as opposed to having to be regenerated, after changes to source schemas.

A Uniform Approach to Inter-model Transformations

Whilst it is a common task in systems integration to have to transform between different semantic data models, such inter-model transformations are often specified in an ad hoc manner. Further, they are usually based on transforming all data into one common data model, which may not contain suitable data constructs to model directly all aspects of the data models being integrated. Our approach is to define each of these data models in terms of a lower-level hypergraph-based data model. We show how such definitions can be used to automatically derive schema transformation operators for the higher-level data models. We also show how these higher-level transformations can be used to perform inter-model transformations, and to define inter-model links.

Developing an Evaluation Methodology for Immersive Learning Experiences in a Virtual World

This article proposes an evaluation methodology for supporting the development of specified learning activities in virtual worlds, based upon inductive methods and augmented by the four dimensional framework [4]. The study undertaken aimed to test the efficacy of the evaluation methodology and to evaluate the broader uses of Second Life for supporting lifelong learners in their educational choices and career decisions. The paper presents the findings of the study and argues that virtual worlds are reorganising how we relate to the design and delivery of learning. This is opening up a transition in learning predicated upon the notion of learning as made up of immersive experiences rather than sets of knowledge to be transferred between tutor and learner. The challenge for tutors remains in the design and delivery of these activities and experience and the approach advocated here builds upon an incremental testing and evaluation of virtual world learning experiences.

A Semantic Approach to Integrating XML and Structured Data Sources

XML is fast becoming the standard for information exchange on the WWW. As such, information expressed in XML will need to be integrated with existing information systems, which are mostly based on structured data models such as relational, object-oriented or object/ relational data models. This paper shows how our previous framework for integrating heterogeneous structured data sources can also be used for integrating XML data sources with each other and/or with other structured data sources. Our framework allows constructs from multiple modelling languages to co-exist within the same intermediate schema, and allows automatic translation of data, queries and updates between semantically equivalent or overlapping heterogenous schemas.

A relaxed approach to RDF querying

We explore flexible querying of RDF data, with the aim of making it possible to return data satisfying query conditions with varying degrees of exactness, and also to rank the results of a query depending on how “closely” they satisfy the query conditions. We make queries more flexible by logical relaxation of their conditions based on RDFS entailment and RDFS ontologies. We develop a notion of ranking of query answers, and present a query processing algorithm for incrementally computing the relaxed answer of a query. Our approach has application in scenarios where there is a lack of understanding of the ontology underlying the data, or where the data objects have heterogeneous sets of properties or irregular structures.

Active rules for sensor databases

Recent years have witnessed a rapidly growing interest in query processing in sensor and actuator networks. This is mainly due to the increased awareness of query processing as the most appropriate computational paradigm for a wide range of sensor network applications, such as environmental monitoring. In this paper we propose a second database technology, namely active rules, that provides a natural computational paradigm for sensor network applications which require reactive behavior, such as security management and rapid forest fire response. Like query processing, efficient and effective active rule execution mechanisms have to address several technical challenges including language design, data aggregation, data verification, robustness under topology changes, routing, power management and many more. Nonetheless, active rules change the context and the requirements of these issues and hence a new set of solutions is appropriate. To this end, we outline the implications of active rules for sensor networks and contrast these against query processing. We then proceed to discuss work in progress carried out in project Asene that aims to effectively address these issues. Finally, we introduce our architecture for a decentralized event broker based on the publish/subscribe paradigm and our early design of an ECA language for sensor networks.