Marc Nanard

Using structured types to incorporate knowledge in hypertext

It has been shown that the famous problem of user disorientation in hypertext is not due to the concept of hypertext itself but rather generally results from the lack of a conceptual model for hypertext application. Unfortunately, in most hypertext systems, the weakness of structure specification mechanisms discourages the development and use of such a model since it is difficult to reinforce hypertext structure and to really incorporate knowledge. A lot of works provide intelligent mechanisms to help navigation but either they use external knowledge or automatically synthesize links from information included in nodes which thereby have no sufficient conceptual value. The present paper focuses on an object-oriented hypertext model (implemented in the MacWeb system) using structured types to incorporate knowledge in hypertext. Concepts and their relationships as well as their instances and their own relationships may be represented. Such a model makes the capture of knowledge at source easier thus allowing a more conceptual navigation, Furthermore, active behaviors may be associated, as methods, to types. This provides a powerful mechanism to help develop structured hypertext as well as task centered applications, by taking advantage of knowledge representation.

Pushing reuse in hypermedia design: golden rules, design patterns and constructive templates

Reuse is increasingly strategic for reducing cost and improving quality of hypermedia design and development. In this paper, based on the design and development of a real hypermedia application, we classify and explore different types of reuse in hypermedia design. We show how constructive templates constitute a practical technique for capturing the specification of reusable structures and components and enabling the automation of the production process. We also discuss connections between constructive templates and design patterns.

Should anchors be typed too?: an experiment with MacWeb

Macweb is a hypertext system that uses types to incorporate knowledge in hypertext. In this paper, we examine an application developed with the system for accessing a technical document base in the context of a task. This application gives us the opportunity to discuss the extension of typing to anchors. We show that attaching knowledge to anchors through types must take into account the context of use of the anchored text. Thus, we introduce the notion of semantic anchoring of concepts within documents. We show how Macweb makes it possible to implement this approach without adding any new features and how it provides an answer to the famous sentence “Don’t link me in”. Beyond the experiment itself, the foundations of the approach and its connection with hypertext systems modeling is presented.

IUHM: a hypermedia-based model for integrating open services, data and metadata

This paper discusses a new hypermedia-based model known as IUHM (Information Unit Hypermedia Model). IUHM emerged as a result of the development of the OPALES system, a collaborative environment for exploring and indexing video archives in a digital library. A basic design requirement of OPALES is that it must permit and support the integration of new services throughout its life cycle. Thus, IUHM depends heavily upon the notions of extensibility and openness.Support for openness, extensibility and late binding of services is provided in the IUHM model by a single reflexive mechanism. This uniform mechanism is used for describing all relationships between arbitrary system entities, including services, data and metadata. The mechanism in question consists of a generic, computable hypertext structure with typed links, known as the Information Unit (IU), and is the minimal structural scheme to which all encapsulated entities comply.We describe and justify the design of the Information Unit, as well as the semantics of its four link types, namely role, type, owner, relative. We further describe the minimal kernel of the runtime layer responsible for the dynamic behaviour specified by the IUHM compliant hypertext network. We discuss the mechanisms involved in the dynamic binding of services and service composition. We illustrate these notions by real-world examples of the integration of metadata services within the OPALES system.

Generating hypermedia from specifications by sketching multimedia templates

This paper presents PageJokey, an object-oriented system for incrementally sketching multimedia templates, The goal is to provide designers with experimental feedback about the ultimate document, beginning from the earliest stages of design. Designers can use existing multimedia objects to create prototype templates, and incrementally generate and test draft versions of the final product using both bottom-up and top=down design approaches, PageJokey supports modular development, using the concepts of’ reuse, abstraction and genericity for generating hypermedia documents.

Media construction formalism specifying abstractions for multimedia scenario design

Abstract Most of the current work on the temporal aspects of hypermedia is oriented towards implementation and rendering. Relatively little work has been directed towards the design of hypermedia artifacts, particularly artifacts comprising large sets of media items with rich sets of temporal relationships. We introduce the media construction formalism (MCF), a formalism permitting the design of media construction abstractions (MCA) for the specification of multimedia scenarios. MCF provides constructs that can be understood and manipulated by designers at different levels of granularity and detail. MCF relies on a temporal model similar to that of SMIL 2.0, but targets design issues. MCF supports abstraction and re-use at the artifact design level and uses the notion of design patterns and the metaphor of roles, players and actors, to provide generic design descriptions. MCF provides an integrated specification of spatial, temporal, and object behavior, including composition which may depend on run time events. MCF provides a designer-friendly environment, incorporating a visual representation of partial designs together with a special-purpose structured editor.

Genre driven multimedia document production by means of incremental transformation

Genre, like layout, is an important factor in effective communication, and automated tools which assist in genre compliance are thus of considerable value. Genres are reusable meta-structures, which exist independently of specific documents. This paper focuses on that part of the document production process which involves genre, and discusses a specific example in order to present the design rationale of mechanisms which assist in producing documents compliant with specific genre rules. The mechanisms we have developed are based on automated incremental, iterative transformations, which convert a draft document elaborated by the author into a genre compliant final document. The approach mimics the manner in which a human expert would transform the document. Transformation rules constitute a reusable and constructive expression of certain aspects of genre. The rules identify situations which appear inappropriate for the genre in question, and propose corrective action, so that the document becomes increasingly more compliant with the genre in question. This process of genre conformance iterates until no further corrective action is possible. This mechanism has been fully implemented. The implementation comprises both a work environment and a rule based language. The implementation relies internally on a general purpose tree transformation engine designed originally for use in natural language processing applications, which we have adapted to handle XML documents.

Concern-Sensitive Navigation: Improving Navigation in Web Software through Separation of Concerns

Traditionally, the use of good techniques to improve software modularity, such as advanced separation of concerns, has no impact in the user experience, for example while navigating Web software. While the intent of these techniques is to simplify evolution and maintenance, navigation design quality is often seen as an unrelated concern. In this paper we present a novel approach for improving navigation in Web applications by using some of the core applications concerns (called navigational concerns) to derive their navigational structure. Using some realistic examples we show that, by carefully using these concerns, we can improve the user experience. Some implementation issues are discussed and a thorough comparison with related ideas in the Web Engineering field is presented.

A Structural Computing Model for Dynamic Service-Based Systems

Traditional techniques for Programming in the Large, especially Object- Oriented approaches, have been used for a considerable time and with great success in the implementation of service-based information systems. However, the systems for which these techniques have been used are static, in that the services and the data available to users are fixed by the system, with a strict separation between system and user. Our interest lies in currently emerging dynamic systems, where both the data and the services available to users are freely extensible by the users and the strict distinction between system and user no longer exists. We describe why traditional object-oriented approaches are not suitable for modelling such dynamic systems. We discuss a new architectural model, the Information Unit Hypermedia Model, IUHM, which we have designed for modelling and implementing such dynamic systems. IUHM is based upon the application of structural computing to a hypermedia-like structure, which thereby operates as a service-based architecture. We discuss the details of this model, and illustrate its features by describing some aspects of a large-scale system, built using this architecture.

A structural computing approach to the production of multimedia document series

The production of multimedia documents of a specified genre from indexed multimedia sources is an important research area. The area adds value to digital library resources and enables the delivery of specific multimedia documents. In this article, we explain how the principles of structural computing may be applied to the production of series of documents complying with some specific genre. The research is inspired by Markov transforms as used in natural language processing. We introduce TTL (Tree Transformation Language), a declarative XML-based formalism for the specification of structural transformation rules. We show, with the aid of a number of examples, how this formalism may be used to specify the narration, rhetoric, and argument structures which respect generic style constraints, and we show how documents are generated. The interpretation of TTL is itself specified as a set of transformation rules, which, together with the SYGMART engine, constitute the SYG-XML environment for producing target documents.