• The goal of the analysis of the dimensions of user modeling is to single out a methodology of the user that need to be modeled, when tackling a specific application problem with specific goals for personalization. Preliminary usability evaluation of small applications (specifically, an active desktop) with limited and simple forms of personalization has been performed, to get a first impression of the techniques that are most promising in these very specific contexts.

During 2002, the research in the above-mentioned areas has been carried on within the following projects:

CAWICOMS (Customer-Adaptive Web Interface for the Configuration of Products and Services with Multiple Suppliers) is a project founded by the European Union within the "Information Society Technology" Programme of the V Framework. It started July 1^st 2000 and ended in December 31^st 2002.

Focus of this project was to enable businesses to market complex customizable products and services by the new ways of electronic commerce. CAWICOMS will develop the technology for:

• A new generation of configurators that will be able to deal simultaneously with multiple suppliers over a network, to interact with other configuration systems as well as with component catalogues, and to deal with different interaction styles and levels, depending on the customer.
• Web-based human computer interaction that will be able to identify the skill-level, preferences, and needs of the customer.

Within the CAWICOMS project, the working unit of the Dipartimento di Informatica of the University of Torino (UTO) focused its own activity on the development of personalization strategies applied in the CAWICOMS user interface to customize the interaction with the user of configuration systems.

Several aspects of the interaction can be personalized. For instance, the layout of the interface, the amount of information to be displayed and the type of questions asked during the configuration of the product/service. The first phase of the project has focused on the last aspect, which strongly depends on the user's knowledge level and interests, and is critical to the usability of the configuration system. The information about the user's interests and skills, together with the underlying domain-specific knowledge about configuration models, is exploited to predict the user's choices during the configuration process. The ultimate goal is to reduce the number of questions to the user during the configuration process and to replace difficult questions which the user might not be able to answer with simpler ones. The decision of the best strategy for the elicitation of information about configuration parameters (e.g., ask the user to choose the preferred value, question her/him about a property of the product/service which is directly related to the parameter and can therefore support the parameter instantiation, exploit a personalized default to set the parameter value automatically, etc.) is made by evaluating alternative elicitation strategies, represented as rules in a rule-based system. As the user interface is dynamically generated during the interaction, the level of detail addressed during the configuration process continuously adapts to the most recent hypotheses about her/his expertise and interests, therefore gaining a reactive adaptation to the user's needs.

The second phase of the project has focused on the improvement of the interaction with the user and on the generation of personalized presentations of product and service solutions. As far as the first topic is concerned, the interaction flow during the configuration process has been updated to support a component-based organization of the configuration process. The user is allowed to select the components of the product/service to be configured first, and she may switch from component to component, depending on her own interests. She also may postpone configuration decisions, when she is uncertain about the parameter values to be selected, and finally she may trigger the automatic configuration of a partial solution, which means that she delegates the system to complete the configuration of the product/service with its own defaults. All these facilities are essential to enhance the usability of a configuration system and require an intelligent user interface managing the interaction context and mediating between the user and the internal configuration engine.

As far as the second topic is concerned (personalized presentation of solutions), a rule based approach has been exploited to develop presentation rules which, parameter by parameter, choose the best presentation strategy (e.g., present the feature in the main page, link it as technical information, link it as supplementary information about the item). The rules are represented, similar to the requirement elicitation ones, as weighted production rules.

It should be noticed that the generation of the personalized user interface is a complex task and requires the coordination of different types of activity. In particular:

1. a user modeling activity, aimed to estimate the customer's interests and knowledge level, on the basis of her/his behavior during the interaction with the system;
2. a conversion activity, aimed to translate (back and forth) the information coming from the Backend (which reasons in terms of configuration problems) into concepts understandable to users, i.e., not strictly related to the management con constraints and configuration problems, but more related to an external (though, possibly very technical) description of the product/service to be configured;
3. a personalization activity, necessary to select the suitable interaction steps, given the problem at hand and the characteristics (expertise, interests) of the individual customer;
4. a dynamic user interface generation activity, as the information presented on the user's screen must be integrated "on the fly", step by step during the configuration process.

The user inputs and the defaults suggested by the Frontend are handed to the Backend and the distributed problem solving mechanism is initiated. After the calculation of results - that are passed back using the generic data exchange mechanism - these results are also presented to the user in a personalized way, i.e., for instance the technical details are omitted.

The project focused on the re-design of the multi-agent architecture developed within the SETA project (SErvizi Telematici Adattativi, 1997-2000, founded by Telecom Italia) to build adaptive Web based systems.

The basic principles behind the design are:

• the identification of roles needed to offer the main functionalities of the system;
• the definition of agents for these roles;
• managment of the interaction between the agents.

A set of specialized agents have been defined. Each of them has a key role (for instance, the communication with the Web, page generation, etc.) and manages the related activities, using knowledge and technologies specific to the task. In particular the architecture includes:

• an agent managing the interaction with the user from a logical stand point, allowing the system to decide the next step of the interaction based on context of the previous interaction and on the user requests
• a set of specialized agents for the user modeling, the selection of information to present and the Web page generation
• some agents have inference capabilities to decompose and solve complex problems

The activity within the project involved also the definition of the internal architecture of a single agent. This architecture has been designed to enable the interaction of heterogeneous agents and includes a wrapper to provide a unified message protocol between different kind of agents. The protocol includes synchronous, asynchronous and multicast types of messages. Moreover, the wrapper allows the agents to manage requests in parallel using the Java thread mechanism. Internally the agents can follow different paradigms: action-based or standard Java objects. For example, the User Modeling component needs to provide user data to other agents, but has also some autonomous activities to carry on, such as revising the user model during the interaction with the system: these activities should be managed independently from the other agents requests. Other agents, like the Personalization Agent, responsible for building the personalized Web pages, simply respond to requests from the browser.

A prototype for personalized tourism services on the Web has been developed, based on this architecture. The system presents to the user artistic attractions as well as restaurants or other useful services. The navigation of the tourist site can be done on the basis of different criteria: information can be found geographically or searching by categories (museums, buildings, restaurants, etc.) or combining the two strategies, for example the user can search for all the Baroque buildings in Torino.

The system has reasoning capabilities, since it is able to schedule the visit during a day by taking into account both the user's choices and other constraints. The system enables the user to select and insert in the agenda a set of artistic attractions of interest and to ask for a suggestion about the schedule of the day, taking into account the selected items and other constraints the user might have (for example the starting time of the visit, morning or afternoon preferences). The agenda is indeed a downloadable service, which may be run on a Java-enabled mobile phone, without requiring the continuous connection with the central server. This is an important technological advance with respect to traditional ubiquitous services, which rely on the communication with the central server to manage the whole interaction with the user, and represents a reasonable way to manage the problem that, at least now, wireless communication is very expensive for the user of a mobile phone.

In the MASTROcarONTE project (carried on in co-operation with Centro Ricerche Fiat and Magneti Marelli Electronic Systems) we investigated the application of adaptation and personalization techniques on board vehicle.

This is a special context of application where the user (driver) operates in peculiar conditions: low bandwidth, non continuous connection, small display, limited input resources and the parallel driving task, which implies that the driver cannot be distracted and cannot browse alternatives form more then some seconds.

In MASTROcarONTE we studied how adaptation (to the driver preferences and capabilities, but also to the context of interaction, including the location, the driving conditions, the time of the day, the presence of passengers) can be a powerful technique to conciliate the use of information systems and the driving task. It is noticeable the number and complexity of these systems is increasing even on average class vehicles and indeed the use of these systems can create serious problems.

In order to experiment the methodologies we developed, we implemented a prototype system that provides tourist information in an adaptive way. The system is distributed with some agents running on the car (we implemented them on the platform used by Magneti Marelli for current generation route planners and on board computers) and some on the service provider. Different forms of adaptation have been implemented, all of them based on user model and context model: personalized selection of information (topic, item, ranking), adaptive presentation, adaptive proactive behavior, with the autonomous activation of the system.

The system has been also tested showing that indeed it can provide useful suggestions and, even more important, can indeed adapt to the conditions of use.