Fourth International Workshop on Web-Oriented SoftwareTechnologies
ˇ:In conjunction with the International Conference on Web Engineering 2004:ˇ
(http://www.icwe2004.org)
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  ACCEPTED ARTICLES


  ABSTRACT ACCEPTED ARTICLES

State-, HTML-, and Object-Based Dialog Design for Voice-Web Applications. The user's interaction with internet information services is usually based on dealing with a graphical interface, but because of the improvements in speech technology over the last years more and more phone speech information services appear. In March 2004 the W3C published the VoiceXML 2.0 recommendation to bring the advantages of web-based development and content delivery to interactive voice response information systems. Although classical modeling strategies for building graphical user interfaces can also be used for their voice based counterparts, there are certain aspects where voice response systems need special attention. For example, an intuitive navigation structure is crucial due to limited possibilities in expressing information to the user. We present a systematic development process which integrates conceptual modeling, rapid prototyping, simulation and system documentation for voice based information services. Following this approach we have implemented a voice based interface for an e-Democracy portal which will be used as an example within this paper.

Semantic Capabilities for the Metrics and Indicators Cataloging Web System. In this paper we thoroughly discuss design and implementation issues for semantic search and navigation to ontology-based metrics and indicators metadata. These semantic search and navigation capabilities are basic functionalities offered by the metrics and indicators cataloging web system in order to accede to related information by registered users. Moreover, this environment can finally allow tools, evaluators and other stakeholders to have service and consultation mechanisms based on a sound specification of the entity type, the attribute and metric definition, related indicators, and calculable concepts, among other metadata. In fact, distributed cataloging systems and interoperable repositories of metrics and indicators can effectively be used to support different quality assurance processes. Particularly, in this work we show the design of the navigational model for semantic search and navigation by the registered user of the cataloging system. The navigational map is a view defined over the metrics and indicators conceptual model [8]. In addition, aspects of the formalization in RDF/S specification and the implementation in the Sesame architecture are shown. Effective and full-fledged quality assurance processes require not only methodological but also up-to-date technological support.

Model Driven Architecture with OOHDM. A model-driven architecture (MDA) transforms a platform independent model (PIM) into a platform-specific model (PSM) before it transforms the PSM into code. OOHDM together with a recently proposed business process extension allows to model hypermedia-based and advanced Web applications by an object model which is a platform-independent. But an OOHDM model cannot directly be used as PIM since it is not an executable model. A behavioral semantics definition of the OOHDM core features and business process makes an OOHDM model executable on a platform-independent Web Application virtual Machine (WAM). As a consequence, an OOHDM behavioral semantics model can serve as a PIM for a MDA. We present two different aspects of the PIM, and give two concrete examples for platform-specific models (PSM) into which the PIM is transformed.

Getting Ready Web Engineering Methods for the Semantic Web. Putting Ontologies into Practice. Current Web Engineering methods develop "closed" web applications from conceptual models. This fact makes difficult the integration and the interoperability of different web applications. In this context it is necessary to establish a technological framework where the application data and functionality could be represented and shared between different web applications. Semantic web languages provide an appropriate framework to achieve these non-functional requirements. Ontologies are proliferating to enable interoperability between Internet-connected applications. Web Engineering methods should be prepared to face up this new challenge. A first attempt in this community is based on the transformation of conceptual schemas into ontologies. This strategy does not take into account navigational and presentation models. This work takes advantage from all these models (navigational and presentation) enriching the web implementations with all the knowledge gathered during the modeling and design process. Our approach provides different ontologies as a basis to enable a more fruitful interchange of knowledge between web applications. We provide a semantic representation of web applications that enables not just to merely access to static information. We also provide a navigational ontology that can be queried through the use of a semantic query language.

WSLS: A Service-Based System for Reuse-Oriented Web Engineering. The development and evolution of Web applications by reusing existing software artifacts is an important goal to reduce costs and to increase quality. Reuse-oriented development is still a difficult task because of the legacy of the Web. Modern component-based technologies and support for service-oriented architectures address the related problems with an increasing set of dedicated solutions. The complexity of such solutions for reusing software artifacts is no longer manageable in an ad hoc manner and without support. In this paper we introduce the WebComposition Service Linking System (WSLS) that addresses this problem providing a reuse-oriented approach to the Web application life-cycle. WSLS is a component-based system, which applies the service-oriented paradigm. It supports issues of composing, discovering and reusing core services. Core services are maintainable, manageable and configurable building blocks - as such they are a unit for reuse and for composition of Web applications. Evolution of the composed core services is supported and guided in a systematic way by the underlying WSLS framework. The system is in use for a project funded by the German government called "Notebook University".

DEPTH: A Methodology for Usability Evaluation of Web Sites Based on Design Patterns and Heuristics Criteria. This paper presents DEPTH (usability evaluation based on DEsign PaTterns & Heuristics criteria) a methodology for performing scenario-based heuristic usability evaluation of Web sites. It is comprised of two operational phases, the preparatory and the execution phase, where specific steps are performed for evaluating the usability along three axis: usability comparison tests among similar Web sites, expert/heuristic evaluation, scenario-based user inspection/enquiry sessions. DEPTH's innovation lies on the use of usability design patterns both as a mean for identifying best practices of usability design as well as for specifying the scenarios and tasks for user inspection. It is also a method for capturing, adapting and refining usability resources of a Web site. DEPTH is also supported by a CASE tool whose functionality is described. Finally, we present a small example demonstrating the basic steps of DEPTH.

MDA applied: From Sequence Diagrams to Web Service Choreography. Web Services and Web Service composition languages for Web Service choreography are becoming more and more important in the area for inter-enterprise application and process integration. A huge amount of work has been done in the area of business process while web service composition languages have been the subject of intense research efforts recently. However the aspects of modeling these software systems have not been studied in detail, in contrast to the definition of business processes where well-known techniques exist. The model-driven architecture (MDA) approach of the Object Management Group is a good starting point for the development of Web Services and Web Service choreography. In this paper we show how platform independent models specified by UML 2 sequence diagrams can be automatically transformed in a Web Service composition language representation. We will start by introducing the notion of Web Services, Web Service compositions languages, and as well as MDA. After setting the global context of our work, we show theoretically and by a small case study how UML 2 sequence diagrams can be refined to Web service choreography.

Semantic Lookup in Service-Oriented Architectures. Lookup of services is an important issues in many distributed systems. This paper deals with lookup in service-oriented architectures, such as Web services, P2P systems, GRIDs, or spontaneous networks. Service-oriented architectures impose specific requirements onto the lookup service, for instance regarding the runtime extensibility of lookup models, runtime extensibility of lookup queries, construction of complex lookup queries, scalability, and fault tolerance. These requirements are not well solved by existing lookup approaches. We propose a semantic lookup service using SemanticWeb ontologies, expressed in RDF. Query scripts are sent from the client to the server and are interpreted at server side using the RDF repository. We also present a safe, scalable, and efficient architecture for defining and querying lookup information using this lookup service concept.

Dialogue-based design for Multi-channel interactions. Lightweight design processes and usable methodologies are increasingly being recognized as "must" requirements for effective design of complex interactive applications. In particular, these requirements imply different factors:
  • It must be easy to teach the design methodology and model to someone (a practitioner, especially): professionals do not have time and resources to invest for learning new methodologies; one of the success factors of "Entity Relationship" (probably the most successful design model, ever) stems from the fact that it was very easy to transmit its basic concept.
  • It must be possible to use the design model for brainstorming and for discussing ideas (among developers, with stakeholders, with possible users, etc.): it is of little use to have a design methodology (model) capable of representing only fully developed solutions.
  • It must require little time to write down design ideas: developers do not like to spend too much time in preliminary activities.
  • It must be possible to move, smoothly, from a general design, to more detailed design, without need for excessive reworking and without need for completeness; in other words, even an incomplete design document must be useful and understandable.
Other factors could be added to the above list. That is enough to explain some of the motivations behind this paper: the complexity and the "richness" of the design model is not what we are aiming for. Simplicity and "usability" of the design model itself is our goal. At a first glance, there is apparently no need for further design models and/or methodologies. In fact, as it will be discussed in the next section, the literature about design models is abundant (OOHDM, HDM, WSDM, OO-H, EORM, WebML, UML WAE, and others). However, besides the technical differences which distinguish current design models, they all share a common feature: they are based upon an information-navigation paradigm to describe the user interaction. This legacy is simply due to the conceptual background underlying the origins of the World Wide Web, which is derived from the Hypertext and the Data Base field: a network of links interconnects pieces of information (nodes). In this scenario, it should not surprise that the nature of the technology available strongly influenced (if not determined) the concepts used to describe, design and evaluate the applications (such as nodes, units, information pieces, entities, slot, links, classes, etc.). Detaching for a moment from the technological mechanisms underlying the application, we argue that it is possible to express the features of the communication between the user and an interactive application in terms of a dialogue, and not in terms of data structures. If this interaction is a sort of dialogue, designers should conceive and craft dialogues and dialogue strategies, and only then derive a sound information architecture.

The UML-Guide for Semantic Web Applications. In this paper, we describe an extension to the UML-Guide for model driven design of semantic web applications. The UML-Guide is used to specify platform independent navigation guides in web applications. Following the MDA approach, a state machine model of such navigation guide described by OWL or RDF is generated using the UML as a source language. The possible applications of such generated state machines are also discussed.

Integrating Agent Services into BPEL4WS Defined Workflows. In the future, Web services and software agents will coexist in the Business Process Management solution space. In our vision, agents will have symbiotic relationships with Web services, harnessing them as externally defined agent behaviors. In this paper we detail the development of a demonstration system that transparently integrates agent services into BPEL4WS defined workflows. The development of the demonstration system illustrates the power of compositional approaches to system creation. It also serves to reinforce the importance of open standards, since the integration of the separate components is dependent upon the interoperability that standards provide. This work is an important first step toward fully integrated agent-based workflow management systems.

Semantic Analysis of a Web site: a Prototype. Many works has been made to improve the users browsing on Web sites notably with the adaptation techniques which allow to guide the users according to their profile in order to direct them to the most interesting pages. Considerable improvements has been made in this domain but it is very difficult to judge the impact of the implementation of such techniques on a site. In this paper, we are going to present a prototype which we set up to study the architecture of a Web site with regard to its semantics. The aim is to try to judge the Web site modelling quality by studying the users browsing with regard to various presented concepts. It allows to have an effective tool to advance the defects of certain Web sites in the optics to improve presentation to the users.

Developing Web Entry Forms Based on METADATA. Reformatting information currently held in databases into Hypertext Mark-up language (HTML) forms suitable for the World-Wide Web (WWW) requires significant effort both in creating the forms initially and their subsequent maintenance. To avoid these costs, we make use of metadata that can be extracted from the catalogue tables in relational database system, using java database connectivity (JDBC). With this development framework the implementation and maintenance of various database backed web applications will be easier, faster and less error prone.

Munich. Germany. July 2004