NCR (National Cash Register) Corporation is pursuing opportunities to make their point of sale (POS) terminals easy to use and easy to learn. To approach the goal of making the technology invisible to the user, NCR has developed an adaptive expert prototype system for a department store POS operation. The structure for the adaptive system, the Retail User Assistant (RUA), is a software platform that observes the operator's actions with hardware and software, evaluates the operator's effectiveness, communicates with the user to provide guidance and training, and adapts itself to compensate for changes in the user's knowledge level. NCR has explored the use of text, graphics, and video to communicate with the POS operator. The development of the visual communication (user interface) for the prototype is discussed, through the design phases of analysis, concept development, prototype, validation, and implementation. Considerable work was done clarifying the visual cues for the operator. Lessons learned in the development process were applied to the RUA to reduce the amount of text and refine the icons used. The verdict is still out on the system for retail use, largely because the cost remains prohibitive. (SLD)