The WE community has already discussed and solved many of the design problems resulting from this complexity. Model-based approaches have been proposed to deal properly with specific Web-oriented modeling features as navigation, presentation, data, and process modeling. New technologies as Web Services, Semantic Web and its associated ontologies, Adaptive Web have been employed to provide a full software production process for developing Web Applications. But too many problems remain open…

The HCI community has addressed some of these problems since a long time. Model-based approaches have been introduced that support the User Interface (UI) development life cycle based on typical models like: task, domain, presentation, dialog. New families of web applications require considering aspects that are not typically addressed in HCI such as process, workflow, jobs, resources, data, and services. However, usability and accessibility have been researched since a long time in HCI. Still many problems remain unsolved…

Since 2001, IWWOST has been an international forum for discussing state-of-the art modeling approaches for Web applications. The first edition was held in Valencia in 2001, the second in Malaga (together with ECOOP 2002), the third in Oviedo (co-located with ICWE 2003), the fourth in Munich (co-located with ICWE 2004), and the fifth in Porto (co-located with CAiSE 2005). The first three editions were sponsored by CYTED, the Iberoamerican Institution for Science and Technology

Since 1993, CADUI has been an international forum for discussing state-of-the-art modeling approaches for user interface design. The first edition was held in Ulm in November 1993, the second in Namur in June 1996 (co-located with DSVIS'96), the third one in Louvain-la-Neuve in October 1999, the fourth one in Valenciennes in 2002, and the fifth one in Funchal (co-located with ACM IUI'2004). The last three editions were published in the Information Systems Series of Kluwer Academics.

IWWOST has been thought as a place for methodologists, designers, and developers to meet and exchange their experiences in the process of building complex Web applications. Usually, IWWOST attendees work on the same problem from different points of view, those supported by the method or design approach of their choice. In this way, IWWOST participants can compare their own approaches with others' and discuss strengths and weaknesses of each approach. Most widely known methods (such as WebML, WSDM, OOHDM, OO-H, UWE, WUML, W2000, etc) have been discussed in previous IWWOST editions.

CADUI has been thought as a place for software designers, developers and researchers who are interested by supported the user interface development life cycle by software. Usually, CADUI attendees work on the same user interface families, but with different modeling techniques and different paths. It has been extensively discussed what types of model are needed, when and where they should be employed. Most widely know models (such as task, domain, user, platform, environment, dialog, and presentation) have been discussed in previous CADUI editions.

The sixth edition of IWWOST is scheduled to take place on June 7-8th, 2006, in Bucharest, Romania co-located with the 5th International Conference on Computer-Aided Design of User Interfaces (CADUI'06, Bucharest, June 7-9th, 2006). This co-location is expected to give opportunities to members of both Web Engineering and Human-Computer Interaction (HCI) communities to better exchange their experience on web applications and to cross-fertilize by looking at what the other community has brought so far.

• WE typically initiates the development life cycle from a conceptual model of the domain -
  HCI typically initiates the development life cycle from a task model. So, where do we start?
• WE prefers uses cases, scenarios, requirements engineering -
  HCI sometimes uses scenarios, but very rarely requirements engineering. So, what's up?
• WE and HCI both rely on scenarios, but their definitions and usages are different. So, which is one is preferable? Does it make sense for them to be really different?
• WE is modeling data very extensively -
  HCI usually relies on a simplified domain model, like a simple class diagram. So what could HCI import from WE here?
• WE often talks about navigation -
  HCI speaks about dialog, control, navigation, conversation. But these terms, e.g., navigation, often mean different things to each community. So, is there something that HCI can improve regarding navigation? And vice-versa?
• WE often consider usability and accessibility as an add-on -
  HCI addresses usability and accessibility as a major concern throughout the development. So, how could we reuse HCI knowledge in WE?
• WE relies on well-defined development method -
  HCI typically relies on a spiral model for iterative design that provides little guidance. So, how could we improve the development process?
• WE and HCI both use development methods, but how are these methods employed in practice, e.g. in industries? So, how do we transfer this to industries and how do we validate?
• WE and HCI frequently abstract design issues in models, but different notations and engineering techniques are used to model the same aspects. So is there a preferable one? Which could be criteria to evaluate these models and notations??