Supporting personalization in a web-based course through the definition of role-based access policies

Role-based access policies model the users domain by means of complex structures where roles, which represent jobs or responsibilities assumed by users, are specialized into more concrete subroles which inherit properties and authorizations from their parents. Such an approach can be applied within the context of educational applications, where different roles are easily identified each of which has different views of the same information items and different capabilities to modify them. Moreover, even though this approach, has only been oriented towards modeling security requirements, it can be extended to support personalized access to the information. In this paper, we describe how to combine the basic principles of RBAC policies and adaptation with a view of providing personalized access to the different types of users of a web-based course. Moreover, we also present Courba, a platform to generate personalized web-based courses using XML to support the definition of access policies.Role-based access policies model the users domain by means of complex structures where roles, which represent jobs or responsibilities assumed by users, are specialized into more concrete subroles which inherit properties and authorizations from their parents. Such an approach can be applied within the context of educational applications, where different roles are easily identified each of which has different views of the same information items and different capabilities to modify them. Moreover, even though this approach, has only been oriented towards modeling security requirements, it can be extended to support personalized access to the information. In this paper, we describe how to combine the basic principles of RBAC policies and adaptation with a view of providing personalized access to the different types of users of a web-based course. Moreover, we also present Courba, a platform to generate personalized web-based courses using XML to support the definition of access policies

Supporting personalization in a web-based course through the definition of role-based access policies

Role-based access policies model the users domain by means of complex structures where roles, which represent jobs or responsibilities assumed by users, are specialized into more concrete subroles which inherit properties and authorizations from their parents. Such an approach can be applied within the context of educational applications, where different roles are easily identified each of which has different views of the same information items and different capabilities to modify them. Moreover, even though this approach, has only been oriented towards modeling security requirements, it can be extended to support personalized access to the information. In this paper, we describe how to combine the basic principles of RBAC policies and adaptation with a view of providing personalized access to the different types of users of a web-based course. Moreover, we also present Courba, a platform to generate personalized web-based courses using XML to support the definition of access policies.Role-based access policies model the users domain by means of complex structures where roles, which represent jobs or responsibilities assumed by users, are specialized into more concrete subroles which inherit properties and authorizations from their parents. Such an approach can be applied within the context of educational applications, where different roles are easily identified each of which has different views of the same information items and different capabilities to modify them. Moreover, even though this approach, has only been oriented towards modeling security requirements, it can be extended to support personalized access to the information. In this paper, we describe how to combine the basic principles of RBAC policies and adaptation with a view of providing personalized access to the different types of users of a web-based course. Moreover, we also present Courba, a platform to generate personalized web-based courses using XML to support the definition of access policies

Tools for Stored Interactive Multimedia

Thesis submitted for the PhD degree

MIDAS: Multi-device Integrated Dynamic Activity Spaces

Mobile phones, tablet computers, laptops, desktops, and large screen displays are increasingly available to individuals for information access, often simultaneously. Dominant content access protocols, such as HTTP/1.1, do not take advantage of this device multiplicity and support information access from single devices only. Changing devices means restarting an information session. Using devices in conjunction with each other poses several challenges, which include the presentation of content on devices with diverse form factors and propagation of the content changes across these devices. In this dissertation, I report on the design and implementation of MIDAS - architecture and a prototype system for multi-device presentations. I propose a framework, called 12C, for characterizing multi-device systems and evaluate MIDAS within this framework. MIDAS is designed as a middleware that can work with multiple client-server architectures, such as the Web and context-aware Trellis, a non-Web hypertext system. It presents information content simultaneously on devices with diverse characteristics without requiring sensor-enhanced environments. The system adapts content elements for optimal presentation on the target device while also striving to retain fidelity with the original form from a human perceptual perspective. MIDAS reconfigures its presentation in response to user actions, availability of devices, and environmental context, such as a user's location or the time of day. I conducted a pilot study that explored human perception of similarity when image attributes such as size and color depth are modified in the process of presenting images on different devices. The results indicated that users tend to prefer scaling of images to color-depth reduction but gray scaling of images is preferable to either modification. Not all images scale equally gracefully; those dominated by natural elements or manmade structures scale exceptionally well. Images that depict recognizable human faces or textual elements should be scaled only to an extent that these features retain their integrity. Attributes of the 12C framework describe aspects of multi-device systems that include infrastructure, presentation, interaction, interface, and security. Based on these criteria, MIDAS is a flexible infrastructure, which lends itself to several content distribution and interaction strategies by separating client- and server-side configuration

HIPPO -- an adaptive open hyptertext system

The hypertext paradigm offers a powerful way of modelling complex knowledge structures. Information can be arranged into networks, and connected using hypertext links. This has led to the development of more open hypertext design, which allow hypertext services to be integrated seamlessly into the user's environment. Recent research has also seen the emergence of adaptive hypertext, which uses feedback from the user to modify objects in the hypertext. The research presented in this thesis describes the HIPPO hypertext model which combines many of the ideas in open hypertext research, with existing work on adaptive hypertext systems. The idea of fuzzy anchors are introduced which allow authors to express the uncertainty and vagueness which is inherent in a hypertext anchor. Fuzzy anchors use partial truth values which allow authors to define a "degree of membership" for anchors. Anchors no longer have fixed, discrete boundaries, but have more in common with contour lines used in map design. These fuzzy anchors are used as the basis for an adaptive model, so that anchors can be modified in response to user actions. The HIPPO linking model introduces linkbase trees which combine link collections into inheritance hierarchies. These are used to construct reusable inheritance trees, which allow authors to reuse and build on existing link collections. An adaptive model is also presented to modify these linkbase hierarchies. Finally, the HIPPO system is re-implemented using a widely distributed architecture. This distributed model implements a hypertext system as a collection of lightweight, distributed services. The benefits of this distributed hypertext model are discussed, and an adaptive model is then suggested

HIPPO -- an adaptive open hyptertext system

The hypertext paradigm offers a powerful way of modelling complex knowledge structures. Information can be arranged into networks, and connected using hypertext links. This has led to the development of more open hypertext design, which allow hypertext services to be integrated seamlessly into the user's environment. Recent research has also seen the emergence of adaptive hypertext, which uses feedback from the user to modify objects in the hypertext. The research presented in this thesis describes the HIPPO hypertext model which combines many of the ideas in open hypertext research, with existing work on adaptive hypertext systems. The idea of fuzzy anchors are introduced which allow authors to express the uncertainty and vagueness which is inherent in a hypertext anchor. Fuzzy anchors use partial truth values which allow authors to define a "degree of membership" for anchors. Anchors no longer have fixed, discrete boundaries, but have more in common with contour lines used in map design. These fuzzy anchors are used as the basis for an adaptive model, so that anchors can be modified in response to user actions. The HIPPO linking model introduces linkbase trees which combine link collections into inheritance hierarchies. These are used to construct reusable inheritance trees, which allow authors to reuse and build on existing link collections. An adaptive model is also presented to modify these linkbase hierarchies. Finally, the HIPPO system is re-implemented using a widely distributed architecture. This distributed model implements a hypertext system as a collection of lightweight, distributed services. The benefits of this distributed hypertext model are discussed, and an adaptive model is then suggested

METHODOLOGIES FOR DESIGNING AND DEVELOPING HYPERMEDIA APPLICATIONS

Hypermedia design, as any other design activity, may be observed according to two points of view: methods which suggest milestones to guide the designer's work and process which concerns the actual detailed behavior of the designer at work. Cognitive studies assess that mental processes involved in any design process show widely shared human characteristics regardless to the used design method. Thereby, they provide general keys to help designers. Thus, a hypertext design environment should equally consider the two dimensions of a hypertext design activity, in particular it should support the natural design process specificities, mainly the incremental and opportunist aspects. The paper focuses on the hypertext design as a computer supported human activity. It examines what is general both in the design methods and in the design process of hypertexts in order to determine which general features are helpful to designers. This analysis has raised from the observation of the behavior of MacWeb users during design tasks. It is related to sound and well known results in cognitive science. The paper also describes how the proposed features are implemented in the MacWeb system.Information Systems Working Papers Serie

"Treating the literary literally" : the reflexive structure of Flann O'Brien's At swim-two-birds

Flann O’Brien’s At Swim-Two-Birds is a complex reflexive novel that explores the creation of fiction. O’Brien’s layered narrative includes several author/characters, each with his own literary theory. This discussion traces O’Brien’s reflexive structure’s development and demonstrates its repercussions on the characters within the novel, and the novel as a whole. Beginning by placing O’Brien’s novel within a critical framework, this study examines each of the four narrative levels and the uses of reflexivity in each. O’Brien builds and dismantles several structures within his narrative levels, and this thesis shows that the basic reflexive structure of At Swim-Two-Birds is the only remaining structure at the novel’s end

Open semantic hyperwikis

Wikis are lightweight, community-editable, web-based hypertext systems, which can be described as a website that anybody can edit. From this collaborative base has grown significant efforts at large-scale knowledge management such as Wikipedia. Recently, ‘semantic’ wiki systems have been developed with typed links, such that the structure of nodes and links is analogous to an RDF graph of resources and arcs: a machineprocessable representation of the relations between articles which can form part of the web of linked data. Despite this, the hypermedia side of wiki systems has so far largely been constrained to the web model of simple embedded, unidirectional links. This research considers the hypertext origins of wiki systems, asks, and answers how the technologies developed during decades of hypertext research may be applied to better manage their document, and thus knowledge, structure. We present experimental evidence supporting the hypothesis that additional hypermedia features would be useful to wiki editors on both macro- and micro-scales. Quantitative analysis of editing logs from a large-scale wiki shows that hyperstructure changes form a substantial proportion of editing effort. Conversely, qualitative user studies show that individual user editing can be better supported by classical but since overlooked hypertext features such as first-class links and transclusion. We then specify an extensive model for a ‘open semantic hyperwiki’ system which draws from these fields, based around first-class links with support for transclusion and advanced functional link types, with defined semantics for the role of versioning and parametric nodes in the linked data world, while mindful to preserve the core simplicity that allows non-expert users to contribute. This is followed by a practical approach to its implementation in terms of an existing experimental modular wiki foundation, and the actual prototype implementation, which has been made available as open source software. Finally, we work through applying the system to a set of real-world use cases which are currently employing classic, non-semantic wiki software, and evaluate the implementation in comparison to a conventional semantic wiki in a user study.EThOS - Electronic Theses Online ServiceGBUnited Kingdo