The enhancement of operator situation awareness (SA) has become a major design goal for automation systems, in a wide variety of fields, including aviation, aerospace, nuclear plants, and advanced manufacturing systems. One can easily grasp that SA has always been needed in order for people to perform tasks effectively and efficiently. For many years, having good SA was largely a matter of learning what to watch and listen for in the field and learning what cues to recognize in the physical process, in other words, training and field experience. Today, operators rely on the principles and design of human computer interaction (HCI) to observe and comprehend the overwhelming amount of process data that can vary rapidly. It is widely accepted that more data does not equate to more information. In many cases, instead of assisting in this issue, automation has only worsened the problem (Endsley & Kiris, 1995; Sarter & Woods, 1995).