Instantiating Web Sites Quality Models: an Ontologies driven Approach Luisa Mich Mariangela Franch Department of Computer and Department of Computer and Telecommunication Technology Management Sciences University of Trento, Italy University of Trento, Italy {luisa.mich}@unitn.it {mariangela.franch}@unitn.it Abstract purpose and domain-independent – it becomes necessary to develop quality models that take also these features One of the most important steps in a Web site quality into consideration (among models having a standard evaluation project is the selection of which aspects to version we can look at WebQual [2] and WebQEM [11]; consider. In terms of methodology, this means defining a an extensive bibliography of models for Web site quality model for the site. In some cases it is possible to use is available at: http://www.economia.unitn.it/etourism/ standardized models, such as “syntactic” models, but this risorseQualita.asp). Basically this means defining is not possible when the evaluation must also consider specialized models that can deal with the unique semantic aspects that have to do with the domain and the specific aspects of a site or sites that will undergo evaluation. The aims of the site or more generally when the evaluation process of definition and instantiation of a model takes aims to consider the “semantics” of the site. The process time and resources and also the input of experts in the of identifying and adapting a quality model requires, domain. In this paper we propose adopting an approach apart from time and resources, the contribution of experts based on the use of ontologies to support the definition of in the domain of the site. In this paper we propose to use detailed semantic models. This approach is an extension ontologies to improve the efficiency of this “instantitation of a methodology “the Quality Model Factory” described processs”. To analyze the feasibility of the approach we in [9] and successfully applied in the area of tourism. It have looked at two applications in the tourism sector. The was applied here to define modular quality models that results, while preliminary, are encouraging. Moreover, make it possible to take into account the characteristics of some critical and delicate points were identified as diverse types of tourist destinations. To do this the models priorities for future research. were developed using a standard model called the 7Loci meta-model [10]. There are two types of “modules” specialized at two different levels of detail: the first, 1. Introduction called the Common module, contains aspects that are common to the sites of all types of tourist destinations, Quality in Web sites is determined by several diverse while the second is comprised of Specialized modules factors, some of which are general and therefore are that contain specific aspects that are found at different considered for all types of site and in all domains. Such types of destinations. To analyze the feasibility of a features include, for example, the correct functioning of methodology based on the use of ontologies to define the site, its conformity with standards of language use or specialized models for Web site quality evaluation, we of accessibility as described in normatives such as the looked at the sites of accommodations and of tourist Web Content Accessibility Guidelines of the W3C destinations facilities. Both are within the tourism domain (http://www.w3.org/WAI/GL/) or the U.S. Section 508 and are highly varied given the diversity of types of Guidelines (http://www.section508.gov/), or standards tourist destination as well as accommodations. Moreover, introduced in Italy through the Stanca law in 2004 the decision to look at the tourist sector – a transversal (http://www.pubbliaccesso.it/biblioteca/documentazione/s sector that includes numerous actors and activities – made tudio_lineeguida/), which requires these standards for it possible to have a general idea of the difficulties and government sites. Other factors or characteristics are challenges, as well as the advantages, of using ontologies more specific and depend on the type as well as the to define quality evaluation models that are specialized domain of the site. Therefore in cases where it is not and modular. possible to use “standard”, “syntactic” models - general- Recent years have seen increased interest in the development and application of ontologies. This has 52 Luisa Mich and Mariangela Franch meant firstly the definition of languages and quality of Web sites becomes a vital strategic factor for environments to set up ontologies. Examples of languages all actors involved. Because tourism is a transversal are DAML (Description Logic Markup Language), OIL sector – or “umbrella industry” – it has contributions from (Ontology Interchange Language), RDF (Resource other sectors, thus an analysis of the sector must have Description Framework) and OWL (Ontology Web input from different fields such as transport, culture, and Language), a semantic markup language for publishing sport, to name a few. This fact explains the existence of and sharing ontologies on the World Wide Web numerous ontologies for tourism. An exhaustive (http://www.w3.org/TR/owl-ref/). Among the more classification can be found in [1]. numerous applications of ontologies are projects related Existing ontologies are both general for the tourism to the Semantic Web, to obtain “an extension of the sector as well as specific, the latter referring to particular current Web in which information is given well-defined domains. In the first category we have the ontology meaning, better enabling computers and people to work in developed for the Harmonise project, whose goal is to cooperation.” [3]. An obvious application of ontologies is develop an ontology-mediated integration of tourist in Web services; among the most recent works and most systems following different standards so that frequently downloaded (was in the fifth position of the organizations can exchange information without changing Top 10 Downloads from ACM’s Digital Library in their data structures (http://www.harmo-ten.info/). In December 2004), we can cite [12]. Also important to note addition there is the Mondeca´s tourism ontology, which is the use of ontologies for the development of software includes tourism concepts from the WTO (World based on reuse [5] and for the management of multimedia Tourism Organization) thesaurus. At this writing this objects in a private and personal environment [7]. ontology has 1000 concepts that describe The proposal described in this paper differs from these accommodations and transportation and a few other insomuch as it is applied at a different level: it is designed secondary elements related to geography, health and to use ontologies to support the development of quality immigration (http://www.mondeca.com/). models that are specialized for Web sites. As such it is a There are over ten elements on the list of domain- conceptual as well as methodological activity, and is specific ontologies that can be useful for the tourist applied at a meta-level with respect to the application of sector, including geographic ontologies, means of the models themselves. transportation ontologies, gastronomy ontologies, etc. [1]. The paper is structured as follows: the first section General – or sometimes called upper – ontologies also gives a general description of ontologies for tourism. exist and aim to gather definitions and concepts that Following this we look at the concept of tourist together make up what is known as unspecialized destination, where we present the classification used to common knowledge. One of the best known of these is apply the “Quality Model Factory” methodology, which WordNet – more appropriately referred to as a lexical we are going to extend to include domain ontologies. The reference system (http://www wordnet.princeton.edu/) third section puts forth two possible applications for the which was extended from solely English into other development of specialized and modular evaluation languages through the EuroWordNet schemes, respectively for hotel Web sites and for tourist (http://www.globalwordnet.org/gwa/wordnet_table.htm). destinations. The conclusion summarizes the preliminary Looking at the ontologies for hotels and tourist results of these applications, underlining the critical destinations (the organizations examined for the points emerging from the application of the methodology feasibility analysis of the approach proposed here) the and which require further study. following facts emerged. Since the concept of hotel is part of common 2. Ontologies for tourism knowledge, the notion is present in WordNet. More specifically, for each concept – in this case hotel – Tourism represents approximately 11% of worldwide WordNet gives information on the generalization, GDP, according to the World Travel & Tourism Council specialization and also on “part of” relationships. A (http://www.wttc.org/). Adding to this is the notable description of the linked concepts is available at growth in the number of tourism-related Internet Answer.com (www.answer.com). In short, in WordNet, transactions in recent years (e-commerce). For example, focusing to concepts that are directly linked to hotel, thus in 2004, 40% of U.S. travelers who use the Internet exploring only relationships represented by arcs going out claimed to make all of their travel purchases online, from the node of hotel, we obtain (see also figure 1): versus 29% in 2003 (www.tia.org). In this context, the Instantiating Web Sites Quality Models: an Ontologies driven Approach 53 hotel is a kind of: projects. Answers.com also provides hypertext definitions • building, edifice — a structure that has a roof and walls and stands more or less (where they exist) found in other sources such as permanently in one place Wikipedia (http://www.wikipedia.org/), which can be kinds of hotel: • hostel, hostelry, inn, lodge — a hotel useful to integrate with those contained in WordNet, and providing overnight lodging for travelers also their translation into diverse languages. • motel, motor hotel, motor inn, motor The more challenging problem is to identify an lodge, tourist court, court — a hotel for motorists; provides direct access from ontology for tourist destinations, although this difficulty rooms to parking area is justified by the complex definition of destination, a • resort hotel, spa — a fashionable hotel concept which, albeit only recently, is assuming an • Ritz — (informal) an ostentatiously elegant hotel increasingly important role in the tourist sector in general. • ski lodge — a hotel at a ski resort Basically, the features that identify a tourist destination Parts of hotel: and distinguish it from what is simply a local offering of a • hotel room — a bedroom (usually with bath) in a hotel product or service that can be of interest to tourists are: - a well-defined geographic area with identifiable Furthering the analysis by using the concept of hotel borders and a territorial identity; room, WordNet gives other information: - the presence of numerous operators with different kinds of hotel room: prospectives and objectives that makes it necessary • adjoining room — a hotel room that shares to devise a shared strategy in presenting the a wall with an adjoining room but is not connected by a door offering consisting of attractions and services • connecting room — a hotel room that shres specifically catering to tourists in the location; a wall with an adjoining room and is connected by a private door hotel room is a kind of: - an understanding of the nature of the potential • bedroom, sleeping room, chamber, demand for the tourist products offered; bedchamber — a room used primarily for sleeping. - awareness of the need to balance tourism’s hotel room is a part of: • hotel — a building where travelers can pay exploitation of resources with ecological, for lodging and meals and other services environmental and community stewardship. A classification of the destinations serving the leisure tourist segment identifies eight distinct types of destination based on the goals for the vacation and the principal attractions present at the destination (table 1) [8]. The table shows key information about the defining features of a destination. Once established, these aspects can then serve as input when determining the requirements and the quality factors for the Web site of the destination. The definition of tourist destination and the classification of diverse types of destination show how the necessary concepts belong to diverse domains. WordNet gives no treatment to the concept of tourist destination. Numerous ontologies were examined as part of this research, but none proved able to cover all the elements that characterize a destination: it is thus necessary to use different ontologies to describe the geographic area, the different attractions, sports, Figure 1 – The graph for hotel (WordNet browser transport, etc. On the other hand, general ontologies Treebolic, http://treebolic.sourceforge.net/) (upper ontologies) contain a lot of information that is not The quantity of information about the concept of hotel useful because it is related to concepts that differ greatly contained in WordNet is exhaustive, an important fact from those used in the tourism context. In addition, since WordNet is free and has been used in many general ontologies for tourism cover only some of the 54 Luisa Mich and Mariangela Franch necessary areas (for example, Mondeca gives good framework. The use of modules derives from the treatment to accommodations and transportation) but not application of reuse of artefacts [13] as a viable practice for some indispensable aspects of a destination (examples for definition of evaluation models. Scalability is obtained being cultural, natural and artistic attractions or events). thanks to the adoption of a general conceptual framework, For this reason we have used WordNet in our for Web site quality, the 7Loci meta-model feasibility analysis, and the decision as to which concepts (www.economia.unitn.it/etourism/pubblicazioni.asp). to consider was informed by the definition of destination This model introduces seven dimensions used to classify itself and by the table. For example, for alpine the numerous features of a Web site that can then be destinations we used the concepts of sport, landscape, evaluated. The dimensions are Identity, Content, Services, nature, etc. We were thus able to simulate the nucleus of Location, Maintenance, Usability and Feasibility. an ontology for tourist destinations. The foundational procedure that serves as the starting point in developing a modular model for a given class of Table 1. Classification of destinations based on their Web sites is outlined in the steps in table 2. principal attractions Type of Well-known Typical attractions found Table 2. Procedure for the quality model factory Main reasons for visiting destination examples at the destination Culture, art, architecture, Museums, historic Urban Capital cities shopping buildings, shops Beaches, organized {1ST PART: DEVELOPMENT OF COMMON AND SPECIALIZED MODULES} Relaxation, enjoyment, Rimini, IF no model for the class of sites currently exists Beach/Sea activities, amusement socializing, sports, night-life Ibiza, Miami THEN FOR each of the 7Loci dimensions pertinent to the project parks, discos, bars, pubs Outdoor sports, landscape Identify the requirements common to all sites in the class and convert them Cortina, into a question; add the question to the Common module; and environment, nature, Nature trails, views, ski Alpine Chamonix, traditional events and trails and slopes, ski-lifts Identify the specific requirements for the type of site under evaluation and Aspen customs, folklore convert them into a question; add the question to the Specialized module; Get back to nature, local Local food producers and ELSE FOR each dimension of the 7Loci: Tuscany, Rural traditions in agriculture and agritours, visits to farms FOR each question of the existing model Provence production and vineyards IF the question is applied to the type of sites in its current form Places equipped for health THEN Add the question to the Common module and therapeutic treatments, ELSE IF the question requires only a formal modification Health treatments, Fiuggi, areas for complete THEN Modify the question and add it to the Specialized Wellness relaxation, diet and exercise Baden- relaxation, medium- and module; programmes, stress relief Baden high-level IF the question is inapplicable to the type of site under evaluation accommodations facilities, THEN check whether there is an alternative question and add it to the fitness Specialized module Renewal or deepening of Place of pilgrimage, {2ND PART: COMPLETION OF COMMON AND SPECIALIZED MODULES} faith, symbolic value of the Lourdes, Religious religious practices and FOR each requirement for the type of site under evaluation location, spiritual retreat and Fatima celebrations Identify the 7Loci dimension it refers to introspection, solitude Adventure, discovery of Cities, historic places, IF no question exists for it in the Common or Specialized module other cultures, understanding rites, customs, THEN IF the question regards all the sites in the class Third Yemen, THEN Add a question to the Common module of tribal life (rites, traditions, celebrations, guided tours, World Madagascar ELSE Add a question to the Specialized module. lifestyle) anthropological contact with non-western investigation local cultures Villages in traditional style Beautiful scenery, isolated but with all modern Exotic and locations, far from tourist Maldives, conveniences, privacy, Exclusive trek, status symbol and Seychelles The procedure has two parts; the first is the untouched natural image environments instantiation of the 7Loci model, reusing where possible a model already defined for one of the types of site in a class. This step is necessary in order to define the model 3. The use of ontologies to define specialized using requirements as the starting point. In the second models part the specific elements for the type of site are identified. When talking about the sites of tourist 3.1 The Quality Model Factory destinations, this means translating these elements into points (characteristics) within the evaluation model; for In [9] we described a modular and scalable approach – example, the unique features of the site for a seaside the Quality Model Factory - to define specialized quality destination will be converted into points in the model models identifying the specific features of tourist used to evaluate that type of site, while features for destination Web sites. Its goal was to introduce a another type of destination (religious, for example) may systematic way to define a “personalized” evaluation not contain those same points. In our previous work we looked at the aspects in table 1, which in general can be Instantiating Web Sites Quality Models: an Ontologies driven Approach 55 found in classification schemes of the sites of a specific hotels. The model consists of 18 questions: four for the category. When describing the procedure, for the sake of dimension Identity, nine for Content, two for Services and simplicity we refer to “questions” to insert in the one for Localization, Management and Usability. The evaluation modules. In reality this is only one way of model is a useful reference to check the results that can be formulating the points or factors of the evaluation model; obtained with the Quality Model Factory which is besides interrogatives (e.g., in boolean questions) they strengthened through the use of ontologies. In this case can also be described in declarative form. we have used the concepts related to hotel in WordNet. In In this paper we want to broaden the approach to be addition, for the requirements of the owner and user, we able to develop models for diverse types of sites, and such have put together information emerging from the research generalization is conceptually based on the use of conducted on the hotels [6]. In this case it meant ontologies. The steps of the procedure where ontologies developing a model more similar to that constructed with can be used are shown in table 2. the contribution of experts, and also applicable to all The logical architecture of the Quality Model Factory hotels. Thus we did not intend to construct different is depicted in figure 2 (a Quality Factory to support models for different types of hotels. “information quality” assessment is described in [4]), where the database “Web site classification” is substituted 3.3. Models for tourist destinations with a database containing the ontologies. Applying the Quality Model Factory approach to tourist destination Web sites without using ontologies produced a series of models, each containing about 100 Web site evaluation project factors that are a reference for evaluating and which can be produced with ontologies [9]. Moreover, we thus obtained important results for the adaption process, where Quality model factory ontologies are necessary to specialize the general-purpose Web sites classification models. Also emerging, in particular, was how the first 7Loci Quality instantiation evaluation two dimensions of the 7Loci meta-model depend more on the type of site (with an average of about 80% of Requirement elicitation Quality models repository specialized factors); about one third are specialized for Quality requirements Validation Services, ten percent for Usability, Maintenance and Localization (related principally to the presence of Requirements repository different target tourist groups). Development of a model for the evaluation of Web site quality for tourist destinations is underway as part of the joint project Quality evaluation Modules IFITT/WTO (www.ifitt.org/)sito. The model foresees two levels of assessment: the first looks at general aspects and therefore at requirements that all tourist destination Web Figure 2. The Quality Model Factory sites must satisfy; the second is called Strategy Based Full Web Site Evaluation. A limitation of the IFITT/WTO model is that there is a measurable gap between the two From among the different actors in the tourist sector levels. Essentially the first level uses a general model for present in the territory we focused on hotels and tourist all destinations while the second must be defined ad hoc. destinations when studying our approach. For both We propose the use of ontologies to specialize the quality categories tourism is the core business and the Web site is models in a systematic way. a strategic tool. For the tourist destination the Web site serves to promote and commercialize the products as well as to support the different actors. 4. Conclusions 3.2. Models for accommodations facilities The project is still underway, the results obtained thus far have revealed the following aspects: In a previous project we built a model for the comparative evaluation of the Web sites of about 200 - The dimensions of the 7Loci meta-model where the use of ontologies is more straightforward are 56 Luisa Mich and Mariangela Franch those which are more “semantic”, thus Content, a version of at least two different types of file that and Services; for these dimensions it is possible to even non-experts can understand. use the hierarchies contained in the ontologies as check-lists to identify aspects for which the site 10. References must give information or support for services. - For the dimension Identity it is necessary to [1]. Bachlechner D., D10 v0.2 Ontology Collection in view of an E-Tourism Portal, E-Tourism Working Draft integrate the ontologies with the aims of the site 5, Oct. 2004, http://www.deri.at/research/projects/e- and be able to connect them to the concepts in the tourism/2004/d10/v0.2/20041005/ ontology that mainly contribute to the creation of the image of the organization; these concepts are [2]. Barnes S. J., Vidgen R. T., WebQual: An usually specializations of “father” concepts; in the Exploration of Web Site Quality, H. Mahrer (ed), Proc. of case of hotels, their specialization is for specific the 8th European Conf. on Information Systems, Vienna, target markets, for example motor hotels. July 3-5, 2000, pp. 298-305 - For all the dimensions of the 7Loci meta-model, [3]. Berners-Lee T., Hendler J., Lassila O., The the combined use of ontologies, of the Semantic Web, Scientific American, May 2001, 284(5): standardized version accompanied by a list of the 34-43 main aims of the site (no more than five elements: e.g., target, business functions, general links), by [4]. Capiello C., Francalanci C., Pernici B., A rule based people with limited experience working in Web methodology to support information quality assessment site quality (undergraduates students), made it and improvemnet, Studies in Communication Sciences, possible to develop “draft” specialized models in a 4(2): 137-154, 2004 short time and which can be rapidly verified and completed by an expert. On the whole, the [5]. Falbo R.A., Guizzardi G., Duarte K.C., Natali methodology proposed makes it possible to A.C.C., Developing Software for and with Reuse: An notably improve the efficiency of the process of Ontological Approach, Proc. CSITeA’2002, USA ACIS, defining specialized models. 2002, pp. 311-316 - Substantial initial effort is required to identify [6]. Franch M., Martini U., Novi Inverardi P.L., Buffa ontologies for the different domains necessary to F., Awareness and exploitation of the potential of the cover the tourist sector. Moreover, existing Web by SMTEs: The case of alpine hotels in Italy and ontologies are heterogeneous with regard to the France, Frew A.J. (ed.), Springer Verlag LNCS 2722: coverage of the domain they refer to. Nonetheless, 318-327, 2005 they can be reused for numerous categories of operators and entities. [7]. Hüsemann B., Vossen G., Ontology-Driven Multimedia Object Management for Private Users – - Statistical analysis of the terms used in sites under Overview and Research Issues, AIS SIGSEMIS Bulletin, 1 analysis provides useful information for the choice (1), April 2004 of ontology, but principally to choose the concepts to use within the ontology to instantiate the quality [8]. Martini U., Da luoghi a destinazioni turistiche. In models. Franch, M. (ed.), Destination management: Governare in - Most existing ontologies are in English language; turismo tra locale e globale, Turin, Giappichelli, pp. 67- but it could be necessary to have ontologies in 111, 2002 (in Italian) other languages. [9]. Mich L., Franch M., Martini U., A Modular - As for their implementation, most ontologies that Approach to Quality Evaluation of Tourist Destination can be used in the tourism context are written in Web Sites: The Quality Model Factory, Frew A.J. (ed.), DAML and some in OWL. This means that if we Springer Verlag, LNCS 2722: 555-565, 2005 want to create environments to support the “Quality Model Factory” it is necessary to extract [10]. Mich L., Franch M., Novi Inverardi P., Marzani P., Choosing the "rightweight" model for Web site quality Instantiating Web Sites Quality Models: an Ontologies driven Approach 57 evaluation, Frew A.J. (ed.), Springer Verlag, LNCS 2722: 334-337, 2003 [11]. Olsina L., Rossi G., Measuring Web Application Quality with WebQEM, IEEE Multimedia 9(4): 20-29, 2002 [12]. Pahl C., Casey M., Ontology support for Web Services Processes, Proc. 9th ESEC and 11th SIGSOFT Symposium FSE, 2003, pp. 208-216 [13]. Pressman R.S., Software Engineering: A Practitioner's Approach, 5th ed., McGraw-Hill, 2001