This paper discusses a methodological approach to define quality models (QM) for Web sites of any kind, including Web 2.0 sites. The approach stresses the practical use of a QM, in requirement definition and quality assessment, during design & development processes or during site operation. An important requirement for such QMs is
, which allows who is in charge of quality management to easily identify the actors in the organization responsible for implementing or improving each specific quality characteristic. A family of QMs is proposed and compared with ISO/IEC 25010 QMs for software products and software-intensive computer systems.