In order to develop accurate, effective augmented reality (AR) systems used in MR, CT guided needle placement procedures, a comparative validation environment is necessary Clinical equipment is prohibitively expensive, often inadequate for precise measurement Therefore, we have developed a laboratory validation system for measuring operator performance using different assistance techniques Electromagnetically tracked needles are registered with the preoperative plan to measure placement accuracy, the insertion path The validation system provides an independent measure of accuracy that can be applied to varying methods of assistance ranging from augmented reality guidance methods to tracked navigation systems, autonomous robots In preliminary studies, this validation system is used to evaluate the performance of the image overlay, bi-plane laser guide, and traditional freehand techniques