Investigation of Cognitive Gains in Object Assembly by Using Augmented Reality

There has been a growing demand for Ready-To-Assemble (RTA) products due to the savings in their transport and labor cost. RTA furniture market is forecasted to increase at a Compound Annual Growth Rate (CAGR) of 4.75% during 2014-2019. Despite the rise in RTA's popularity, non-intuitive assembly instructions continue to plague widespread adoption of RTAs. The lack of cognitive support in these 'static manuals', increases the mental workload during the installation. Evidence warns that perceived difficulties during RTA assembly may lead to emotional frustration or even physical damages to the user and the product. Yet, no technologies have been developed to assist the RTA assembly efficiently. From the standpoint of cognitive processing, people perceive it difficult to assemble RTA products. The main reasons being the lack of spatial problem-solving abilities or continual creation of mental representations of the product-in-assembly. This study hypothesizes that with additional spatial information along with mental representation, a cognitively heavy RTA assembly can relieve the mental workload of users as well as decrease the installation time and errors. Augmented Reality (AR) enabled Microsoft HoloLens headset was used to enhance the physical parts with computer-generated virtual objects. This investigation is a comparative study in which four tasks - simple without AR, simple with AR, complex without AR, and complex with AR - are used to measure the effectiveness of the AR application on 14 subjects. AR has demonstrated its potential to improve the spatial awareness thereby reducing the demand for the cognitive resources. However, no application has been developed to test AR on the scale of RTA furniture. The application would guide the entire installation process by showing which parts to pick up and how the parts are connected. Overall, the ability to overlay and register information on the workspace in spatially meaningful ways is likely to trigger diverse types of AR applications for advanced aid and instructional tools. However, it is crucial to understand specific cognitive gains that can be earned from the use of AR applications. This knowledge will help evaluate the current tools and justify design improvements. Results of this study showed that AR application reduced the installation completion time and errors, but there was an increase in the cognitive load. Also, the spatial problem-solving ability of the person was improved. Task complexity was found to be an important characteristic that impacted the applicability of the AR application. Finally, this study explained the factors that can improve the design of an AR app and gave insights into the advantages and disadvantages of Microsoft HoloLens.