International Journal of Web Applications Margaret Sazio, Miriam A. M. Capretz 5 3 2013 http://www.dline.info/ijwa/fulltext/v5n3/2.pdf Web services facilitate the sharing of resources between groups within a collaborative environment. Privacy is an important concern when sharing data. Access control can be used to protect privacy by limiting the access privileges to the underlying resources. This paper outlines a framework for applying access control to data providing Web services. The framework makes use of ontologies allowing for a clear description of the functionality offered by the services within the collaborative environment. The implementation of the framework is described using XACML as a basis for the access control. XACML is extended to function with the defined ontologies in order to provide fine-grained access control. Finally, a case study is worked through showing how the proposed framework could be applied within a healthcare environment.