Proper layout and positioning of building components is essential for an accurate and productive construction process. Knowing the specific location and position where a building component belongs in real-time (instantaneous), would enhance the crafts person's performance significantly (Beliveau, 1992a). The Real-time Position Measurement (RtPM) system was developed to increase productivity and accuracy in the construction industry by providing the crafts person real-time position and measurement information of specific building locations or components. This measurement information is relayed to the crafts person through the human interface, which consists of graphical navigational maps and alphanumeric displays. Two experiments were conducted. Experiment A tested the graphical computer interfaces and Experiment B compared the graphical interfaces versus an alphanumeric interface. Both experiments simulated building component positioning tasks. Subjects acted as construction workers whose jobs were to accurately place simulated building components on specified target locations utilizing the RtPM system. Participants used the RtPM's navigational maps, displays and/or coordinate system to place several anchor bolts onto specific locations on the concrete piers. The experiments provided data on the speed and accuracy of positioning tasks while the subject was using the RtPM system. The data consisted of the time required to accomplish each building component positioning task and the accuracy of the subject's placement of the receiver pole on the target point. The results of Experiment A indicate that a heading-up map is better for navigational tasks using the RtPM system than that of a vector-up map. The treatment conditions which incorporated a heading-up map gave lower navigational times than those using a vector-up map. Subjects were also accurate across all treatment conditions in Experiment A. The results of Experiment A suggest that participants interpreted the navigational information across all conditions in the same manner thus achieving similar accuracies. The results of Experiment B indicate that the graphical interface provides good directional information and a high degree of accuracy when subjects perform positioning tasks using the RtPM system. The alphanumeric format, while providing a high degree of accuracy, did not provide a fast and effective way of navigation using the RtPM system. Graphical displays should be incorporated into the new software design for the RtPM system. These navigational experiments should provide a means for designing future RtPM surveying system software for the human user. Humans are critical components in most systems and are often neglected during the design process. The results from this research could significantly enhance the effectiveness by which humans interact with the RtPM system. / Master of Science