  An augmented reality (AR) environment includes a set of digital elements with
which the users interact while performing certain tasks. Recent AR head-mounted
displays allow users to select how these elements are presented. However, few
studies have been conducted to examine the effect of the way of presenting
augmented content on user performance and workload. This study aims to evaluate
two methods of presenting augmented content - world-locked and head-locked
modes in a data entry task. A total of eighteen participants performed the data
entry task in this study. The effectiveness of each mode is evaluated in terms
of task performance, muscle activity, perceived workload, and usability. The
results show that the task completion time is shorter and the typing speed is
significantly faster in the head-locked mode while the world-locked mode
achieved higher scores in terms of preference. The findings of this study can
be applied to AR user interfaces to improve content presentation and enhance
the user experience.
