Hi, I'm Oliver Nowak and I present the work "Shaping Textile Sliders: An Evaluation of
Form Factors and Tick Marks for Textile Sliders". For this, I worked together with René Schäfer,
Anke Brocker, Philipp Wacker, and Jan Borchers from the RWTH Aachen University.
The most common way to control smart home devices like lights, fans, and media devices
are movable remote controls, and speech.
While remotes are not necessarily always there when they are needed, speech might be inappropriate
in certain scenarios. For example, when watching a movie.
With textile interfaces, we can integrate unobtrusive controls for smart home devices
where they are needed. For example into furniture like sofas and
beds, but also in decoration like table runners and pillows.
While we found many technical contributions in the field of textile interfaces, we found
few recommendations for the form factors of textile controls.
Since sliders can be used in many scenarios in the home—for example when setting the
brightness of the lights—we wanted to start with those and investigate how those should be
designed. Especially, how different form factors of sliders can help users orientating
when using the sliders eyes-free.
For this, we created a set of different sliders. The simplest element you can find on textiles
are single seams. So, we decided to use those as probably most unobtrusive slider.
In the following, we call those sliders Path sliders. Furthermore, we created
closed-shaped sliders that have a two-dimensional body like a rectangle.
Since textiles do not have to be simply flat, we created sliders with different profiles. We
differentiate between sliders that are raised from the surface—in this case simply embroidered
onto the fabric—and sliders that are recessed. Recessed sliders were fabricated by adding
a 3 mm thick padding under the fabric and embroider the slider on the fabric together with the padding.
Similarly, we created profiles for closed-shaped sliders.
We differentiated between sliders those outlines were embroidered into the fabric without the
addition of padding—so, the inner parts are flat—and sliders that have a raised
or recessed inner area.
As already mentioned, we were interested in slider designs that help the users estimating
their position on the slider. Therefore, we changed the shapes to offer
different features that help orientating.
The Rectangle slider served as baseline. Here, the participants could only use the start
and end of the slider as orientation help.
The Tick Mark slider is a rectangle slider that uses the well-known concept of tick marks
to offer help at discrete 10% steps.
With the W slider, we used another way to communicate the discrete steps within the
slider. There, the direction change should indicate that the next 25% step of the slider
is reached.
The Triangle should continuously help the user
by increasing the distance of the upper and the lower seam when moving from left to right.
With Rainbow, the slope of the slider should help estimating the current position.
And for practical reasons, we added Horseshoe as a variant of Rainbow that is bent more
to save some space.
To investigate what of those form factors is preferable, we conducted a user study with
20 people in the age of 22 to 28 years.
The study was divided into four parts: Path vs. Closed-shaped sliders
The comparison of profiles for Path sliders and for Closed-shaped sliders.
And the comparison of the different shapes.
For each phase, the sliders were placed on
a padding behind a sight protection wall. Behind this wall, the participants could explore
all slider variants. For all phases, except the ones for the shapes,
we provided a Rectangle, W, and a Horseshoe slider of each form factor to enable the participants
to test several movement patterns.
In the shape phase, each shape was tested separately. There we asked the participants
to find some locations on the slider to get a first impression of the real usage scenario.
We found that raised Path sliders and flat Closed-shaped sliders
performed significantly worse in all comparisons.
Participants' comments made clear that those were much harder to recognize.
However, if you have to use such sliders, the rankings and comments suggest to use Path
sliders since they were easier to follow.
Recessed and raised closed-shaped sliders were rated similarly, however, we found that
recessed sliders are significantly more comfortable to use and are more suited for sliding gestures.
The W slider was most disliked by our participants. They criticized that it was too complex to
recognize eyes-free. Furthermore, our observations and the participants
comments showed that the idea of the Triangle slider did not work well and that participants
rather used start and end points for the orientation. Rainbow, Tick Mark, and Horseshoe were ranked
best by the participants.
After we knew from our first user study that we should use recessed sliders and that tick
marks & curved sliders work well, we measured user performance in our second user
study with 20 participants. The goal was to investigate how well the slider designs
can help the users orientating and thus, selecting a value more confidently.
For this, we split the study into two parts: A selection task and an estimation task.
For both the setup was similar to the first user study.
For the selection task, the participants were asked to set a certain percentage value on
the slider. They moved from a homing position underneath the slider to the slider and did
the selection.
Next to the two curved sliders, we used Rectangle sliders with a varying amount of tick marks.
We used a Blank slider as baseline and sliders with tick marks that represent 50, 33, 25,
20, and 10% steps.
We found that 20 and 25% steps improve the selection accuracy significantly in comparison
to the Horseshoe, Blank and Rainbow slider.
Surprisingly, the participants were significant faster with 25% steps than 20% steps.
However, the participants were also fastest with 25% steps.
Looking at the participants’ rankings, we found that any additional help was appreciated.
20 and 25% steps got the highest ranks, while 33% steps made the estimation harder.
So far, we determined what people can do to find a position on a slider, but to do this,
they had to explore the most of the slider before doing the selection since all tick
marks felt the same. Our next question was whether varying the tick mark design can
help the user to get a good estimation of their position when starting the selection.
For this, we again tested curved sliders and used the regular tick mark design as baseline.
Additionally, we varied the tick marks by rotating them, changing their size and position, and
changing the number of dots per tick to create different tactile sensations.
While all of those are based on three equally distributed tick marks, we additionally tested
a design where the density of tick marks should help the user orientate.
For the estimation task, we guided the users to a certain location using a plastic slide
such that they could not get any hints of their position while approaching the slider.
From that position, we asked the participants to move as little as possible but as much
as necessary to estimate their initial position.
In the estimation task, all estimations on sliders with equidistant tick marks were significantly
better than on curved sliders.
Leaving the rotating tick marks out, equidistant tick marks improved the estimation significantly
in comparison to the curved sliders and when the tick marks get denser.
The gesture footprint was significantly reduced when using equidistant varying tick marks.
The participants’ rankings and their ratings for distinguishability are in favor for dotted,
elevating, and rotating tick marks. With Dotted performing slightly worse.
Based on the results from both studies, we present a first set of design recommendations
for textile sliders and their tick marks: If you cannot use any padding for the
slider, prefer Path shapes. Otherwise, use raised or recessed sliders.
Especially recessed sliders support sliding gestures well.
For typical use cases, use 3 to 4 tick marks. And if a slider should enable fast and
confident value estimation, our tick mark designs with rotating or moving
ticks were preferred by our participants. Thank you very much for your attention!