Cognitive engineering

Designing and maintaining Web applications is one of the major challenges for the software industry of the year 2000. In this paper we present Web Modeling Language (WebML), a notation for specifying complex Web sites at the conceptual level. WebML enables the high-level description of a Web site under distinct orthogonal dimensions: its data content (structural model), the pages that compose it (composition model), the topology of links between pages (navigation model), the layout and graphic requirements for page rendering (presentation model), and the customization features for one-to-one content delivery (personalization model). All the concepts of WebML are associated with a graphic notation and a textual XML syntax. WebML specifications are independent of both the client-side language used for delivering the application to users, and of the server-side platform used to bind data to pages, but they can be effectively used to produce a site implementation in a specific technological setting. WebML guarantees a model-driven approach to Web site development, which is a key factor for defining a novel generation of CASE tools for the construction of complex sites, supporting advanced features like multi-device access, personalization, and evolution management. The WebML language and its accompanying design method are fully implemented in a pre-competitive Web design tool suite, called ToriiSoft.

Web Modeling Language (WebML): a modeling language for designing Web sites

The exponential growth and capillar diffusion of the Web are nurturing a novel generation of applications, characterized by a direct business-to-customer relationship. The development of such applications is a hybrid between traditional IS development and Hypermedia authoring, and challenges the existing tools and approaches for software production. This paper investigates the current situation of Web development tools, both in the commercial and research fields, by identifying and characterizing different categories of solutions, evaluating their adequacy to the requirements of Web application development, enlightening open problems, and exposing possible future trends.

Tools and approaches for developing data-intensive Web applications: a survey

The conceptualization and empirical validation of web site user satisfaction

In this paper we analyze the process of hypermedia applications design and implementation, focusing in particular on two critical aspects of these applications: the navigational and interface structure. We discuss the way in which we build the navigation and abstract interface models using the Object-Oriented Hypermedia Design Method (OOHDM); we show which concerns must be taken into account for each task by giving examples from a real project we are developing, the Portinari Project. We show which implementation concerns must be considered when defining interface behavior, discussing both a Toolbook and a HTML implementation of the example application.

Systematic hypermedia application design with OOHDM

the conceptual hypertext data model and abstract navigational model [22] can benefit directly from software engineering approaches. Fundamental differences , however, make a pure transposition of techniques both difficult and inadequate. An important part of hypertext design concerns aesthetic and cog-nitive aspects that software engineering environments do not support. This article focuses on the hypertext 1 design task itself as a computer-supported activity. In it we provide guidelines for developers of hypermedia design environments to facilitate the user's design process. A hypertext design environment can support both formal hypermedia design techniques and the actual design process successfully. While we take advantage of object-oriented terminology to describe certain concepts, the lessons of this article apply to all formal design techniques. Thus we neither proscribe nor detail a formal design model. Instead we examine the general human-factor aspects of the design process to determine which features help designers most. We also enumerate the requirements hypermedia design environments have that other types of computer applications do not. This analysis arises from observing users and students during design tasks, and is grounded in sound and well-known results in cogni-tive science. It builds upon our experience in developing LIRMM's MacWeb 2 hypermedia development environment [14–16]. One may consider hypermedia design, as with any other 49 J o c e l y n e N a n a r d a n d M a r c N a n a r d Hypertext Design Environments and the Hypertext Design Process mproving the quality of hypermedia design and reducing its cost is an important challenge for the information industry. One way to tackle the problem is to provide hypertext designers with appropriate development environments. Hypertext engineering environments that provide sets of integrated tools boost designers' efficiency and effectiveness. 1 Hypertext and hypermedia are handled similarly in design. Both refer to organized sets of information linked by semantic relationships, and therefore are indistinguishable in this article. 2 MacWeb [14, 15] is a knowledge-based hypertext system developed at LIRMM since 1989. To avoid any confusion, note that it is unrelated to the WorldWide Web client developed later with the same name. We used the name MacWeb first (and have published articles referring to it that predate the WWW client). design activity, from two points of view or dimensions: • prescribed formal design techniques to produce the design • observations on how people actually conduct the design process Most …

Hypertext design environments and the hypertext design process : Designing hypermedia applications

Hypertext design environments and the hypertext design process

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.

Using structured types to incorporate knowledge in hypertext

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.

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

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.

Marc Nanard

Papers

Hypertext design environments and the hypertext design process : Designing hypermedia applications

Hypertext design environments and the hypertext design process

Using structured types to incorporate knowledge in hypertext

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

Should anchors be typed too?: an experiment with MacWeb