1 Introduction
In 2000, Hall, Hall and Tate [1] proposed the inclusion of the Human Computer Interface as Level five of the Joint Directors of Laboratory (JDL) Data Fusion Process Model (Figure 1). The aim of the introduction of a level 5 process was to highlight the need to explicitly consider the interaction between automated data fusion processes and a human-in-the-loop analyst/decision-maker. The level-5 process ([2], [3]) is considered by its proponents as a human-side analog to the sensor-side level 0 process that had previously been introduced by Steinberg et al [4]. That is, level 0 processing was originally introduced to recognize the increasing evolution of smart sensors having embedded processing such as pre-detection fusion, advanced signal and image processing and pattern recognition. In effect, the level 0 process enhanced sensor oriented functions that affected the other traditional levels (1–4) of fusion processing. Using a similar analogy, Hall et al [1] argued that advances in human computer visualization tools, cognitive aids, and collaboration tools should be explicitly considered as advances that affect the human side of fusion processing and their effect on the traditional levels of fusion processing. JDL Data Fusion Model with Level 5 [3]