Hello everyone, my name is Argenis Ramirez Gomez, and it is my pleasure to be presenting
Gaze+Hold on behalf of my co-authors Christopher Clarke, Ludwig Sidenmark and Hans Gellersen.
Gaze+Hold is an eyes-only interaction technique that builds on the ability to close one eye
while gazing with the other one to leverage the eyes as two separate input channels for
direct manipulation. Gaze+Hold utilises the closure of one eye
to modulate the state of interaction while the open eye provides continuous input until
the re-opening of the closed eye. Eyes-only control
is compelling for a wide range of contexts where other input is unavailable or inconvenient.
Existing eyes-only interfaces are grounded on the use of the combined eyes and continuous
gaze tracking for pointing that is complemented by discrete selections,
for instance, by other eye movements such as
fixations and dwell time. These approaches have two key limitations.
Firstly, they could create problems of feedback and unintended input - for example, the Midas
touch – as the pointer moves with every eye movement
and there is no distinction of whether the movement was intended as a pointing action,
Or incidental to viewing. Secondly, the use of the eyes is exclusive
for either pointing or click-equivalent actions. As a consequence, continuous direct manipulations
are not well supported. For example, the eyes-only equivalent to a
mouse movement while pressing a button to move an object has to be mapped to a succession
of gaze interaction steps to First trigger the selection of the command,
then, the selection of the object, and finally, the target position.
In this work, we introduce Gaze+Hold to extend the expressiveness of eyes-only interaction.
The key idea is to leverage the eyes as two separate sources of input to support continuous
direct manipulation by delimiting the interaction states with the closing and opening of one
eye, whilst continuous input of the open one controls the explicit interaction.
Let’s take a close look at how Gaze+Hold interactions work, for example, to enable
drag and drop: First the Closing of one eye initiates input
and selects the file The movement of the other eye provides continuous
input to drag the file until the opening of the closed to complete
the interaction with a drop This draws a distinct design space and style
of eyes-only interaction that we explored to showcase the utility, and flexibility of
Gaze+Hold with a constellation of example applications.
For instance, Selection and moving of objects
Multiple object selection Menu Navigation and selection
Panning and scrolling Zooming or scaling
Or Navigation and teleportation among other examples.
These examples open up a design space for eyes-only interaction, for which we distil
key design considerations such as the utility of the gaze input at the different stages
of the technique; the relevance of its accuracy; position; feedback; and the use of one or
both eyes to allow multiple states of interaction, for instance, to enable the configuration
of different states or grabbing of tools with the eyes.
We invite you to find more information in the paper.
The use of Gaze+Hold relies on one-eyed gaze as continuous input,
raising usability questions from both a technical and a user perspective that we addressed in
a user study. Firstly,
Due to the requirement of the user to keep on eye closed for the duration of input, the
performance of Gaze+Hold is dependent on the user’s ability to keep one eye closed
while using the other for input; and the input’s quality of the binocular
tracking system when estimating gaze when only one eye is available.
Moreover, we investigated the usability, workload and user preferences when using Gaze+Hold
to determine how the choice of eye – and eye dominance – affects performance.
For instance, whether there is a preference for using one eye over the other, and how
this manifest in choices user make when interacting spontaneously.
We conducted a user study with 12 participants to establish the practicality and effectiveness
of the technique with two tasks: First, a drag-and drop task resembling the
multi-directional Fitts’ Law task with 16 targets.
We compared the performance of Gaze+Hold with the dominant eye, and non-dominant eye against
a baseline of gaze input with both eyes open with manual activation of interaction states
with a button press. This aimed to assess the trade-off in performance
for gaining the advantage of gaze only control. Secondly, we assessed the spontaneous choice
of eye for Gaze+hold with a realistic desktop application scenario in which participants
had to use the technique to move files into folders.
The results from the user study show how as expected with a binocular eye-tracker,
gaze estimates are less accurate when they are temporarily based
on a single eye, while the coordination of gaze with eye closing
increases effort. Nonetheless, participants were as effective
with Gaze+Hold as with the baseline of binocular gaze. Speed and accuracy were lower than with
both eyes open, but users gained the advantage of relying uniquely on their eyes for input.
Notably, all users were able to use Gaze+Hold with either eye closed, and the choice of
dominant versus non-dominant eye for manipulation had no significant effect on performance,
usability and perceived workload. To finalise, We want to leave you with some
takeaways of this work. First, the Gaze+Hold technique is unique in
leveraging the eyes as separate channels for complementary input.
Secondly, Gaze+Hold is not as fast as binocular gaze, but closure of one eye is highly effective
for delimiting gaze input and switching between interaction states without needing other devices
or modalities. Thirdly, our work shows that users are effective
with Gaze+Hold, performing equally well with either eye, allowing flexibility to access
different input modes as well as dynamic configuration of eyes-only control.
Finally, Gaze+Hold opens up a new design space for eyes-only techniques and interfaces, for
which this work provides a foundation and key design considerations.
We invite you to find out more details in the full paper and to stay in touch. Thank
you for listening.