Computer assistance for breast conserving surgery requires a guidance method to assist a surgeon in locating tumor margin accurately. A wide array of guidance methods can be considered ranging from various pictorial representations, symbolic graphical interfaces as well as those based on other sensory cues such as sound. In this study, we present an experimental framework for testing candidate guidance methods in isolation or in combination. A total of 22 guidance approaches, based on stereographic, non-stereographic, symbolic and auditory cues were tested in a simulation of breast conserving surgery. Observers were asked to circumscribe a virtual tumor with a magnetically tracked scalpel while measuring the spatial accuracy, time and the frequency with which the tumor margin was intersected. A total of 110 studies were performed with 5 volunteers. Based on these findings, we demonstrated that a single view of the tumor with a stereo presentation in conjunction with an auditory guidanc...