The Likelihood Alarm Display (LAD) is a new type of alerting system display that forms an optimal interface between an intelligent or "expert" computer monitoring subsystem and a human pilot. In a LAD display, the alerting signal provided to the human operator contains information about the computed likelihood of the problem as determined by the intelligent automated subsystem. This encoded likelihood information enables more accurate problem diagnosis and improved allocation of operator attention. The LAD should result in improved system performance and reduced operator error, especially under high levels of pilot workload. System performance with LADs has been evaluated for several different types of tonal and speech display codes.STATUS: Phase I Only-