The focus of this research was to examine how effectively augmented reality (AR) displays, generated with a wearable computer, could be used for aiding an operator performing a manufacturing assembly task. The research concentrated on comparing two technologies for generating augmented reality displays (opaque vs. see-through), with two current types of assembly instructions (a traditional assembly instruction manual vs. computer aided instruction). The study was used to evaluate the effectiveness of the wearable based augmented reality compared to traditional instruction methods, and was also used to compare two types of AR displays in the context of an assembly task.

For the experiment, 15 subjects were asked to assemble a computer motherboard using the four types of instruction: paper manual, computer aided, an opaque AR display, and a see-through AR display. The study was run as a within subjects design, where subjects were randomly assigned the order of instruction media. For the AR conditions, the augmented environments were generated with a wearable computer, and viewed through two types of monocular, head-mounted displays (HMD). The first type of HMD was a monocular opaque HMD, and the second was a monocular see-though HMD. Prior to the experiment, all subjects performed a brief training session teaching them how to insert the various components of the motherboard in their respective slots. The time of assembly and assembly errors were measured for each type of media, and a questionnaire was administered to each subject at the end of each condition, and at the end of the experiment to determine the usability of the four instructional media.

The results of the experiment indicated that both augmented reality conditions were more effective instructional aids for the assembly task than either the paper instruction manual or the computer aided instruction. The see-through HMD resulted in the fastest assembly times followed by the opaque HMD, the computer aided instruction, and the paper instructions respectively. In addition, subjects made fewer errors using the AR conditions compared to the other two types of instructional media. However, while the two AR conditions were a more effective instructional media when time was the response measure, there were still some important usability issues associated with the AR technology that were not present in the non-AR conditions. Many of the subjects indicated that both types of HMDs were uncomfortable, and over half expressed concerns about poor image contrast with the see-through HMDs. Finally, this thesis discusses the results of this study as well as implications for the design and use of AR and wearable computers for manufacturing assembly tasks.