Abstract- Previous research has demonstrated that Augmented Reality can reduce a user's task response time and mental effort
when completing a procedural task. This paper investigates techniques to improve user performance and reduce mental effort by
providing projector-based Spatial Augmented Reality predictive cues for future responses. The objective of the two experiments
conducted in this study was to isolate the performance and mental effort differences from several different annotation cueing techniques
for simple (Experiment 1) and complex (Experiment 2) button-pressing tasks. Comporting with existing cognitive neuroscience literature
on prediction, attentional orienting, and interference, we hypothesized that for both simple procedural tasks and complex search-based
tasks, having a visual cue guiding to the next task's location would positively impact performance relative to a baseline, no-cue condition.
Additionally, we predicted that direction-based cues would provide a more significant positive impact than target-based cues. The
results indicated that providing a line to the next task was the most effective technique for improving the users' task time and mental
effort in both the simple and complex tasks.
This paper makes a number of contributions. The design and implementation of two target-based and three direction-based SAR predictive
cues for a button pressing task. Two user studies of varying task complexity determined one direction-based cue to be vastly superior, as
measured by task performance and self-reported mental effort for simple and search-based procedural tasks.
In summary, we hypothesize for this study:
Hypothesis HI All predictive cues have a positive effect on performance.
Hypothesis H2 Direction-based cues lead to superior performance
over target-based cues.
Hypothesis H3 Task complexity will impact the user performance of
the cues.
The results from both experiments determined that SAR predictive
cues enhance the user experience compared to having no additional cue,
especially in search-based procedural tasks. We also discovered that
direction-based SAR cues produce fewer errors in complex procedural
tasks than target-based cues. Furthermore, from the comparison of
both experiments, the difficulty of the task was determined to have an
impact on how the cueing techniques performed. Finally, the LINE cue
performed the best in concerning all measurements, regardless of task
complexity.
From our results, we suggest that an optimal predictive SAR cue
in simple or complex procedural task should unambiguously identify
the next target action, while avoiding interference between the current
and upcoming targets. The results of this study can be applied to any
real-world scenario where the user has to perform a procedural task in
which the procedure is known beforehand.
Future research into applying these cues to various other tasks with
real-world distractors is one of the next steps. We would additionally
wish to investigate a task that mimics real-world activities more closely,
such as the button sequence for starting a machine, in the case for
manufacturing. A second activity is an assembly task for notifying
the user of the next object in the task and where to place that object.
A third area of investigation is how the augmented reality techniques
could be applied in medicine, such as highlighting areas of the body for
a skin cancer check or training for or the order instruments in a surgical
procedure. Another direction of investigation is the development of
direction-based predictive cues that are not as overt as the LINE cue.
The current substrate for the SAR cues are projected onto is a neutral
white background, but real world control panels have vastly more
complex textures.
The present results lay the foundations for investigating interindividual differences in regard to the benefits of particular AR cueing
techniques, based on established cognitive tests. A final direction to undertake is to determine if these results can be replicated with other AR
display technologies, such as OST HMDs, VST HMDs, and handheld
display devices.