A Multi-granular Linguistic Hierarchical Model to Evaluate the Quality of Web Site Services

The explosion in the use of Internet has contributed to arise a lot of web sites that offer many kind of services (products, information, etc). At the beginning the quality of these web sites was not too important because the most important fact was that people knew that there was a web site because there was not a big competence. But recently, there are many web sites related to the same topics in Internet and the quality of their services has become a critical factor. Different evaluation approaches for different types of web sites have been developing [2, 22, 35] in which the users provide their opinions in a predefined numerical scale to evaluate their services. Nevertheless, the information provided by users is related to their own perceptions. Usually, human perceptions are subjective and not objective, therefore to assess perceptions with precise information is not very suitable and the results are not accurate. Therefore, in this chapter we propose a linguistic quality evaluation model to evaluate the services offered by the web sites. The use of the fuzzy linguistic approach has provided good results managing human perceptions. Our proposal will consist of a hierarchical model to evaluate the services offered by general purpose web sites, such that, it will choose a few quality dimensions to be evaluated, where each one has different criteria. The users will provide their knowledge about these criteria by means of linguistic assessments. But different users can have different knowledge about the web site’s criteria, so the evaluation model should take into account this point. Therefore, our model will be defined in a multi-granular linguistic information context, such that, different users can express their opinions in different linguistic term sets according to their knowledge. In order to develop this evaluation model we shall use different tools and resolution schemes based on decision techniques that are able to deal with multi-granular linguistic information.