Labyrinth, an abstract model for hypermedia applications. Description of its static components

In information technology, models are abstract devices to represent the components and functions of software applications. When a model is general and consistent, it represents a useful design tool to unambiguously describe the application. Traditional models are not suitable for the design of hypermedia systems and, therefore, specific design models and methodologies are needed. In the present article, the requirements for such models are analysed, an overview of the characteristics of the existing models for hypermedia applications is made and an abstract model fulfilling the analysed requirements is presented. The model, called Labyrinth, allows 1) the design of platform-independent hypermedia applications; 2) the categorisation, generalisation and abstraction of sparse unstructured heterogeneous information in multiple and interconnected levels; 3) the creation of personalisations (personal views) in multiuser hyperdocuments for both groups and individual users and 4) the design of advanced security mechanisms for hypermedia applications.     

HADT: Hypermedia application development tool for tourist applications

This paper describes an authoring tool prototype design for the development of hypermedia applications. The system is based on a generic object oriented data model suitable for hypermedia, that has been designed and implemented in our department. The model is extensible for integrated multimedia manipulation and provides an enhanced linking system. The design aims at a general purpose hypermedia application development tool which may well be used for the development of tourist applications. It is of special interest in the Greek tourist market since tourism contributes considerably to the national income of Greece. Current technology provides the hardware for manipulation of multimedia information and increases the quantity and quality of information flow between the user and the machine. Thus in a travel agency environment it would be desirable to have an interactive multimedia demonstration helping the user find places of interest in any context (physical beauty, archaeological interest, tourist infrastructure, possible itineraries etc.). Such a tool would be very effective compared with the static presentation of brochures. HADT has the potential to fulfil these needs when it is developed, and in this paper we explore such possibilities. Furthermore, research directions for future work are discussed.     

Modelling hypermedia and web applications: the Ariadne Development Method

The development process of hypermedia and web systems poses very specific problems that do not appear in other software applications, such as the need for mechanisms to model sophisticated navigational structures, interactive behaviors, interfaces with external applications, security constraints and multimedia compositions. Even though experience, modelling skills and abstractions can be borrowed from existing software design methods, such as object-oriented modelling, hypermedia developers need specific mechanisms to analyze and design using entities that belong to the hypermedia domain (such as nodes, links, anchors and space and time-based relationships). Moreover, hypermedia methods should provide mechanisms to deal with all the aforementioned features in a progressive and integrated way. In this paper, we present the Ariadne Development Method (ADM), a software engineering method that proposes a systematic, flexible, integrative and platform-independent process to specify and evaluate hypermedia and web applications. ADM has been shown particularly useful in complex systems involving a huge number of users with different abilities to access information, with a complex structure where a huge number of nodes have to be organized in a clear way to produce specifications that are discussed by people with an heterogeneous background. This is the case of ARCE, a Latin American project where 21 countries are cooperating to produce a web platform to improve assistance in disaster mitigation situations.     

Toward support for hypermedia on the World Wide Web

As organizations rush to embrace the World Wide Web as their primary application infrastructure, they should not bypass the benefit of hypermedia support. The Web's infrastructure can serve as an interface to all interactive applications and, over time, will become the graphical user interface model for new applications. Ubiquitous hypermedia support should become the jewel of the Web environment. Through Web integration, hypermedia could become an integral part of every interactive application. With the proper tools to support hypermedia in Web application development, it will become second nature for developers and individual authors to provide supplemental links and hypermedia navigation. However, as organizations adopt the Web as their primary application infrastructure, designers may use Java and other tools to recreate current application functionality, and not take advantage of the Web's hypermedia-augmented infrastructure. If users, designers, MIS departments and organizations don't demand hypermedia support, hypermedia may get lost in the frenzy of Web integration     

Automatic generation of instructional hypermedia with APHID

This research investigates the use of patterns in designing adaptable, flexible hypermedia applications. While patterns are particularly applicable to software design, they can also be used to assist designers of other types of applications. We have developed a method (APHID) that guides a hypermedia creator through the analysis and design process. The method ensures that good design principles are followed, both for the hypermedia application and for the interface that presents the hypermedia application. Our method uses a concept map, constraints, and patterns (instructional and presentation) to support partial automation for creating hypermedia applications. We also present a prototype software system that uses the APHID method to create instructional hypermedia applications semi-automatically. The applications created using APHID are tailored to specific types of learners. We conclude with a claim that this approach is applicable not just to instructional hypermedia, but to the larger problem of generating adaptable interfaces.     

Constructing Geographic Digital Libraries using a Hypermedia Framework

This paper presents an object oriented hypermedia database framework for designing and building digital libraries, which are treated as enhanced hypermedia applications. It is based on combining and extending results from two domains: the navigation characteristics of hypertext systems, and the view mechanism and the persistent storage management facility of an object oriented database management system. As a result, users can alternate between two integrated types of interaction modes. The hypertext dimension of the framework allows navigation via static and dynamic hyperlinks; the object oriented database support enables querying by content and metadata management. The framework includes still a digital library design methodology that guides the implementation of digital libraries over the OODBMS. This proposal integrates hypermedia and DL concepts to a database environment, being instantiated on the realm of geographic data.     

CRITON: A Hypermedia Design Tool

The WWW has turned into a development and run-time environment for large-scale and complex applications. Such sophisticated applications are being deployed in increasing numbers without having been developed according to appropriate methodologies, tools and quality standards. The reason is not only that the hypermedia industry resists to utilize formal methods, but also that these methods and corresponding tools are very few and of dubious standards. The consequence is that the hypermedia applications being developed are of poor functionality and lack qualities such as modifiability, usability and maintainability. Especially the design phase is one of the phases that lack sufficient support from methods and CASE tools. This paper presents CRITON, a cross platform tool, built to support a hypermedia design method within an integrated environment. CRITON manages all three aspects of hypermedia design: conceptual design, navigational design and graphical user interface design, utilizing well-established theories and practices from software as well as hypermedia engineering. It employs these designs to generate a preliminary, exemplary form of the hypermedia application for the purpose of assessing the designs before the implementation phase.     

Helping users help themselves

Application-learning problems are a perennial design challenge. This persistent help-seeking behavior is forcing designers to wonder if any technologies for designing interactive help will satisfy the user as much as asking a real person. In addition to hypermedia applications, the paper considers several technologies explored as help systems. These technologies can easily provide a knowledgeable apprentice to help users accomplish their tasks, but they do pose challenges for interface design     

一种面向对象的开放式超媒体引擎

从讨论超媒体引擎的设计原则和设计方法入手,提出了一种基于面向对象数据库管理系统的开放式超媒体引擎.由于引入了元对象建模,该引擎不仅可以表达复杂的超媒体语义,而且可以直接支持开放性链接协议,从而实现了对第三方应用的开放性.     

Automating Hypermedia for Decision Support

Many ‘first generation’ hypermedia systems were designed to support applications, which do not require the dynamic and general characteristics necessary for our domain --- decision support systems (DSS). The heart of our research is a dynamic model of hypermedia incorporating virtual structures and computation, which we call generalized hypermedia. Generalized hypermedia broadens and automates the ‘static’ or non-virtual notion of first generation hypermedia for a knowledge-based DSS shell. The shell provides a hypermedia-style interface for navigating among DSS application models, data and reports. Such a shell should support applications in a variety of fields, e.g., engineering, manufacturing, finance, and therefore must provide hypermedia support as general, system-level functionality Generalized hypermedia superimposes a hypermedia network on a DSS application, generating all hypermedia nodes, links and link markers dynamically from the application's standard, non-hypermedia knowledge base. In this paper we demonstrate how automating hypermedia can enhance decision making with a DSS. We describe generalized hypermedia and discuss the challenges presented to it by a dynamic, real-time environment.     

Cohesive design of personalized Web applications

Good software engineering practices, such as separating concerns and identifying patterns, simplify the critical design decisions in building personalized Web applications. The authors use the object-oriented hypermedia design method (OOHDM) for constructing customized Web applications. Incorporating well-known object-oriented design structures and techniques, OOHDM produces flexible Web application models. Designers can add personalized behavior to these models with minimal code manipulation, and reasoning over design objects yields better insight into the personalization process. Although this article casts the discussion in terms of the OOHDM primitives, the ideas presented can be easily applied to other design approaches, such as WebML     

Engineering the Design of Usable Hypermedia

This paper presents a systematic method for designing hypermedia that are easy to use for various types of users, along with its application to a specific case study. The design phase is supported by the use of task models. We have identified criteria that indicate how information in task models can be used to identify links, design presentations, and structure the data of the hypermedia considered. Different types of users imply different task models and thus different hypermedia designs. We then show how the design obtained was evaluated using both empirical testing and metrics for hypermedia navigation. We discuss the results obtained by these two evaluation methods and how they affected the original design.     

A hybrid system approach for supporting digital libraries

A digital library (DL) consists of a database which contains library information and a user interface which provides a visual window for users to search relevant information stored in the database. Thus, an abstract structure of a digital library can be defined as a combination of a special purpose database and a user-friendly interface. This paper addresses one of the fundamental aspects of such a combination. This is the formal data structure for linking an object oriented database with hypermedia to support digital libraries. It is important to establish a formal structure for a digital library in order to efficiently maintain different types of library information. This article discusses how to build an object oriented hybrid system to support digital libraries. In particular, we focus on the discussion of a general purpose data model for digital libraries and the design of the corresponding hypermedia interface. The significant features of this research are, first, a formalized data model to define a digital library system structure; second, a practical approach to manage the global schema of a library system; and finally, a design strategy to integrate hypermedia with databases to support a wide range of application areas. Received: 15 December 1997 / Revised: June 1999     

JPernLite: extensible transaction services for the WWW

Concurrency control is one of the key problems in design and implementation of collaborative systems such as hypertext/hypermedia systems, CAD/CAM systems, and software development environments. Most existing systems store data in specialized databases with built-in concurrency control policies, usually implemented via locking. It is desirable to construct such collaborative systems on top of the World Wide Web, but most Web servers do not support even conventional transactions, let alone distributed (multi-Website) transactions or flexible concurrency control mechanisms oriented toward team work-such as event notification, shared locks, and fine granularity locks. We present a transaction server that operates independently of Web servers or the collaborative systems, to fill the concurrency control gap. By default, the transaction server enforces the conventional atomic transaction model, where sets of operations are performed in an all-or-nothing fashion and isolated from concurrent users. The server can be tailored dynamically to apply more sophisticated concurrency control policies appropriate for collaboration. The transaction server also supports applications employing information resources other than Web servers, such as legacy databases, CORBA objects, and other hypermedia systems. Our implementation permits a wide range of system architecture styles     

User‐interface design heuristics for developing usable industrial hypermedia applications

Shop floor operators urgently need help to cope with the pressures of the present manufacturing context. One proposed solution is industrial hypermedia applications (IHA). A review of published papers on IHAs has shown that while the potential benefits of such applications, if accepted and used by operators, are well documented, user‐interface design aspects are not. In other words, the rationale used for the user‐interface design is not explained. This article fills the gap by drawing on human–computer interaction and hypermedia literature to present user‐interface design guidelines or heuristics. The latter were incorporated in 2 IHAs developed for this study. Shop floor operators empirically assessed the IHAs through usability trials held in the workplace and provided data on their perceptions of the IHA's ease of use. The findings show that the 7 design heuristics contributed to the usability of the IHAs. However, developers should not apply the design heuristics in isolation but should also elicit user characteristics and task domain. © 2002 Wiley Periodicals, Inc.     

A Manifesto for Hypermedia Usability Research

Following a brief introductory review of existing findings, we discuss key aspects of hypermedia usability in the light of the differences, and similarities, between the design of hypermedia applications and that of more conventional user interfaces. Conversational interaction, techniques for visualisation of structure, considerations of relevance and importance, and the provision of selective views of knowledge bases are all considered. We then focus on the role of analogy and of dynamism in hypermedia interface design, with particular emphasis on the advantages and pitfalls of using metaphor. The concluding section summarises our manifesto for future hypermedia usability research.     

一个动态超媒体映射引擎

文章首先介绍了传统应用软件和超媒体应用软件的差异,指出了超媒体应用系统的特征和对最终用户的吸引力.在此基础上,建立了一个动态超媒体映射引擎的模型,它可以透明地为大多数传统应用系统增加超媒体的界面.文章最后给出了在WWW上实现的一个DHyME(dynamic hypermedia mapping engine)实例.     

A case study in systematic hypermedia design

Hypermedia structuring and navigation requires design methodologies different from those developed for standard information systems. This case study details our successful application of relationship management methodology (RMM), a hypermedia systems analysis and design methodology, to ACM SIGLINK's LINKBase. LINKBase is a World Wide Web (WWW) application, which dynamically generates WWW pages from a relational database containing information about hypermedia-related events such as conferences, publications, authors, and sponsoring organizations. We describe our experience applying RMM in this case study, summarize design lessons we learned in the process, present extensions to RMM, discuss human–computer interaction (HCI) aspects of RMM, and ground our work in the hypermedia design and HCI literature. Our experiences should encourage hypermedia and WWW developers to utilize systematic design techniques to build highly usable and useful WWW applications.     

Hypermedia systems for improving knowledge,understanding and skills in engineering degree courses

Two contrasting computer based learning applications have been introduced into engineering degree courses. Both are based upon the “open” hypermedia approach, and both use Microcosm to organise and link resources, and Toolbook to present much of the material. One of the applications uses a traditional, “linear”, tutorial style approach, while the other presents students with a design problem and provides them with a large and diverse amount of poorly structured information which the students have to use to generate an engineering design. Both applications were evaluated in several ways and analysis of the responses leads to the conclusion that carefully written computer based applications can be effective not only for teaching basic knowledge at this level, but can also be used as a means of allowing students to develop skills in complex areas such as generating solutions to open-ended mechanical engineering design problems.     

Designing hypermedia information retrieval systems for multimedia art catalogues

Abstract

Multimedia art catalogues present a number of recurring characteristics in both the type of data and the users involved, and in the type of operations required. Typical data include textual catalogue cards manageable through an information retrieval system (IRS), as well as textual captions, images, video, and speech, organizable as a hypermedia network. In this paper we propose a model for the design of these applications, and discuss its effectiveness in improving the quality of the application. The model exploits a multi-level design approach to organize data and access structures of the IRS, while the Entity-Relationship (E-R) approach, tailored to model hypermedia applications, is adopted to describe the structure of the documents and their links.