Abstract: This paper presents a Controlled Experiment (CE) for assessing testing strategies in the context of Access Control (AC); more precisely, the CE is performed by considering the AC Systems (ACSs) based on the XACML Standard. We formalized the goal of the CE, and we assessed two available test cases generation strategies in terms of three metrics: Effectiveness, Size and Average Percentage Faults Detected (APFD). The experiment operation is described and the main results are analyzed.