Hi i'm Margaret and i'll be presenting switching between standard pointing
methods with current and emerging computer form factors.
Modern tablets and laptops support many different input methods. Some are
absolute direct pointing methods, like touch
and pen, and some are indirect relative methods,
like trackpad and mouse.
In the past there have been works that examine the performance of pointing
methods like Cockburn et al, who examined the
performance of pen mouse and touch and Cassidy et al, who compared pen and
touch. However the sole work we were able to
find that directly examines the time taken to switch between pointing methods
was published 40 years ago! While evaluating text selection
performance Card et al found that it took an average of 0.4 seconds to move
between keyboard and mouse. This indicates that there is a clear gap
in literature for examining switching between input methods on modern devices.
Our first study examines switching between pointing devices on a touch
screen tablet, specifically touch, pen, trackpad, and mouse.
Our task was a modification of a 2d fits task, where tokens were arranged in a circle.
Participants dragged a color token to a target (indicated with dashed lines), then tapped the center target.
Then they performed the docking task with the other pointing method used in that block.
First we hypothesized the time to switch between pointing methods is asymmetric. This makes sense, as when you use touch
you simply have to move your finger to the target, while when using the mouse
you need to grasp the device, locate the cursor, then move the cursor to the target.
This leads into our second hypothesis that switching to an absolute method like touch is faster and less error
prone than switching to a relative method like mouse.
Next we hypothesize that switching between methods with the same input
mapping will be faster and less error prone than switching between methods
with different input mappings. The thinking is that the user can
continue using similar motor movements for both pointing methods without having
to plan the switch in subsequent pointing action.
Finally, we hypothesize that a switch involving the pen will be slower and
more error prone compared to the equivalent switch with touch
as switches of the pen require the pen grip to be adjusted for the pen to be
tucked while using the other pointing method.
Now, how do we measure the time taken to
switch between pointing methods? We adapt the subtraction method from
previous mode switching works. By flattening our task into a 1d
representation we can see there is a clear interval after tapping the center
circuit with the red method and selecting the next docking token with
the blue method where the participant has to switch between pointing methods.
If we could subtract the time to use the red method on its own from this interval, we could get the raw method switching
time for a trial. So how do we get these times?
Again we borrow from mode switching works.
We bracket switching blocks with baseline blocks for each method used in
the switching blocks. In these baseline blocks the
participants only use a single method with no switching
By having baselines before and after the switching blocks we compensate for learning effects
We used a within subjects design with six switch conditions - so one condition
for each pair of the four devices. There were 14 switch trials per block or
two turns around a circle, and seven baseline trials per block or a
single turn around the circle. We recruited 12 participants all of which were right-handed.
Now here are our results for switch time.
We found that switching between pen and touch was fastest while switching to trackpad or mouse was slower
next we examined switching on a tablet-sized foldable device pictured here.
Again we recruited 12 right-handed participants. We added a new hypothesis as well but
switching on the foldable device would be slower and more error prone than on the tablet
We also slightly altered the task instead of using seven docking tokens arranged in a circle
we used eight with tokens placed symmetrically on and around the folds of
the device like so, where the blue line represents the fold of the device
Now for the results of our second experiment we found that switch times
were higher overall on the foldable device
and switching to trackpad wasn't as slow as it was on the tablet
Also, switching between pen and touch wasn't as fast as it was in our first experiment.
We found that hypothesis 5, or our hypothesis that switching would be slower and more error prone on the
foldable device was the only hypothesis to be fully supported
the others were only partially confirmed or not supported
Participants preferred conditions that required less hand movement
and they also didn't like dragging their finger over the fold of the laptop when using touch.
Our results inform future inter-direction design for existing and emerging form factors and can even extend klm modeling.
in summary we provide empirical evidence for pointing methods switching time and errors for modern input methods
Thank you for your time