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 technologica...

The goal of this paper is to argue the need to approach the personalization issues in Web applications from the very beginning in the application's development cycle. Since personalization is a critical aspect in many popular domains such as e-commerce, it important enough that it should be dealt with through a design view, rather than only an implementation view (which discusses mechanisms, rather than design options). We present different scenarios of personalization covering most existing applications. Since our design approach is based on the Object-Oriented Hypermedia Design Method, we briefly introduce it, emphasizing the way in which we build Web application models as object-oriented views of conceptual models. We show how we specify personalized Web applications by refining views according to users' profiles or preferences; we show that an object-oriented approach allows maximizing reuse in these specifications. We discuss some implementation aspects and compare our work with related approaches, and present some concluding remarks.

Web sites are progressively evolving from browsable, read-only information repositories to web-based distributed applications. Compared to traditional web sites, these web applications do not only support navigation and browsing, but also operations that have affects their contents and navigation states. Compared to traditional applications, web applications integrate operations with the built-in browsing capabilities of hypermedia. These novelties make web application design a complex task that requires the integration of methods and techniques developed in different "worlds". This integration is achieved in this paper by extending and customizing the Unified Modeling Language (UML) with web design concepts borrowed from the Hypermedia Design Model (HDM). Hypermedia elements are described through appropriate UML stereotypes. UML diagrams are also tailored to model operations and relate them with hypermedia elements. The approach is exemplified by describing the design of a web-based conference manager.

. In this paper, we argue that web applications are a particular kind of hypermedia applications and show how to model their navigational structure. We motivate our paper discussing the most important problems in the design of complex Web applications. We argue that if we need to design applications combining hypermedia navigation with complex transactional behaviors (as in E-commerce systems), we need a systematic development approach. We next present the main ideas underlying the Object-Oriented Hypermedia Design Method (OOHDM). We show that Web applications are built as views of conceptual models. We next present the abstraction primitives we use to design the conceptual and navigational structure of Web applications and describe the view definition language. We introduce navigational contexts as the structuring mechanism for the navigational space. Some further work on designing Web applications with OOHDM is finally presented. 1 Introduction: Web Applications are Hype...

There has been a recent increase in the number of published design patterns for hypermedia. Some of these patterns have been evolving, while others have remained untouched. This paper attempts to list all the patterns currently known, tracing the different publications in which they have appeared. The patterns are scrutinized and refined: some patterns are unified into one; some are deemed special cases of other patterns; some patterns are renamed. At the same time, we propose to rewrite the patterns in a vocabulary that is uniform, and to use similar pattern templates. We then discuss the creation of a design patterns system, which organizes the patterns and assists the designer in the process of recognizing the problems and their potential solutions. Finally, we propose a subset of the patterns which should conform a catalog of basic patterns; this catalog will attempt to address the most common problems found during the design of hypermedia applications. Keywords: hypermedia design...

In this paper we present an architecture for building families of rich Web applications. We first characterize current trends in Web applications, from read-only Web sites to sophisticated applications where complex distributed transactions must be supported. We next some design principles for building Web applications, and give the rationale for separating application behavior from navigation and interface issues. We briefly argue the need for developing a product line architecture for simplifying the systematic construction of different families of applications. We next describe the main components of our architecture explaining how we manage to decouple application specific aspects from technological aspects (such as dynamic page generation and persistence) that can be eventually solved by reusing of-the-shelf components. We show how to build application frameworks using this architecture using a concrete example of an electronic CD store.

In this paper we introduce Web design frameworks as a conceptual approach to maximize reuse in Web applications. We first discuss the need for building abstract and reusable navigational design structures, exemplifying with different kinds of Web Information Systems. Then, we briefly review the state of the art of object-oriented application frameworks and present the rationale for a slightly different approach focusing on design reuse instead of code reuse. Next, we present OOHDM-frame, a syntax for defining the hot-spots of generic Web application designs. We illustrate the use of OOHDM-frame with a case study in the field of electronic commerce. We finally discuss how to implement Web design frameworks in different kind of Web platforms. 1 Introduction Building complex Web applications such as ecommerce applications is a time consuming task. We must carefully design their navigational architecture and user interface if we want them to be usable. We must understand the user tasks w...

. Business information received from advanced data analysis and data mining is a critical success factor for companies wishing to maximize competitive advantage. The use of traditional tools and techniques to discover knowledge is ruthless and does not give the right information at the right time. Data mining should provide tactical insights to support the strategic directions. In this paper, we introduce a dynamic approach that uses knowledge discovered in previous episodes. The proposed approach is shown to be effective for solving problems related to the efficiency of handling database updates, accuracy of data mining results, gaining more knowledge and interpretation of the results, and performance. Our results do not depend on the approach used to generate itemsets. In our analysis, we have used an Apriori-like approach as a local procedure to generate large itemsets. We prove that the Dynamic Data Mining algorithm is correct and complete. Keywords: Data Mining, Dynamic Approach,...

In this paper we present a novel approach for designing the interface of rich internet applications. Our approach uses the Abstract Data Views (ADV) design model allowing expressing in a high level way the structure and behaviors of the user interface. Additionally, by using advanced techniques for separation of concerns it allows to create complex interfaces as oblivious compositions of simple interface atoms. Using a simple illustrative example we present the rationale of our approach, its core stages and how it is integrated into the Object Oriented Hypermedia Design Method (OOHDM). Some implementation issues are finally analyzed.

WebML is a high-level language for specifying the content structure of data-intensive Web applications, and the organization and presentation of such content through a hypertext structure. This paper concentrates on the conceptual design of structural schemas and hypertexts, which represents the core aspect of the WebML design process. In particular, the paper introduces a set of WebML skeletons, i.e., abstract and simplified versions of structural and hypertext schemas that are recurrent within Web applications. Then, it shows how skeletons can be composed to obtain several WebML application frameworks, which provide a classification of Web sites from the viewpoint of their predominant information-delivery mission (or business model). WebML skeletons and frameworks can be assumed as the initial start-point of design sessions, as well as paradigms for better understanding and classifying data-intensive Web applications.