Portais de bibliotecas sistemas de avalia？？o de qualidade dos servi？os: The Evaluation Systems of the Quality of Services

in a world where the information technologies perform an important role in the dematerialization of elements and relations, the libraries must adapt themselves to the new reality and must have their services and products in the web. thus, the evaluation of the quality of services undertakes a vital role in the competitiveness of the organization. one of the main instruments of the new services is the website for which there are generic or specific evaluation methods directed to different public with or without the application of the technology. therefore, the models of quality evaluation that allow to evaluate websites during the creation, development and maintenance processes are describe. those processes configure different dimensions and factors demostrating and identifying a prevalence for the use, context and interaction of the websites.