Hello to everyone, my name is Giuseppe Melfi I'm a researcher at Karlsruhe Institute of
Technology and I will present our work on TPad, a mobile audio-tactile system for graphics
used at schools with students with visual impairment.
Nowadays, a lot of information is presented graphically in educational environment, we
have for example histograms, flow charts, scatter plots, maps, and so on but students
with blindness don't have access to this visual information.
The topic of our work is how to make graphic accessible to blind student.
A possible solution is to provide an alternative text, a textual description of the graphic
that will be accessible for the students using a screen reader.
This is the only method that we currently have for complex graphics, but it has also
some limits.
In particular the descriptions are produced manually by experts, that try to don't introduce
any interpretation of the graphic and the most important problem is that exploring graphics
to discover information independently is a fundamental part of the learning process.
A second solution, currently in use, is to provide to the student a tactile graphic.
An image with raised surface that can be felt with the fingertips.
A problem that comes with this solution are the extra lines and labels that make the tactile
graphic complex to read.
The second issue is the space for including text in Braille that is extremely limited.
This means that some information is put it into a legend, a key and the tactile graphic
required oft also a global caption for a general overview on the graphic.
This means that this solution is affected by a fragmentation of the information problem.
To solve the problems of the previous methods, we propose TPad: A Mobile Audio-Tactile System
for Graphics Used at School.
It is composed by four parts.
A standard tablet, in our experiment an iPad pro.
A frame printed with a 3D printer.
To easily fix the tactile graphic on the tablet.
A mobile application that was developed as a cross-platform App.
And a Raspberry Pi that works as Server.
On the server we have also a repository with all the audio-tactile files.
A converter.
The system is compatible with standard SVG files but thanks to the converter the teacher
can also load into the repository file other formats (For example Draw Open Document).
And a back-end with some features for the teacher.
Last, the server can also provide a hot spot for a local network.
Useful in case an internet access is not available in the classroom.
To explain how the system works I will show you a short video.
To use TPad, the first step is to fix the frame on the tablet and to open the TPad App.
Then we load the audio-tactile graphic using the QR code.
Each tactile element, provided with audio description, is highlighted with a short tone
by the system.
With a double-tap we get the description using the speech to text technology.
Using the back-end, a remote control is also available.
The teacher can load the desired tactile graphic on all connected devices during the lesson.
In our study we compared three different methods to explore a tactile graphic.
In the first two methods, the most important graphic elements are labeled in Braille and
the actual information of the graphic is provided in a legend, printed in Braille for the first
method, and saved in a Word file for the second method.
The last method is our TPad system.
The test was conducted with five blind students, thanks to the collaboration of Tilly-Lahnstein-School
of Nikolauspflege in Stuttgart.
The study hypotheses were: The Audio-tactile graphic (TPad method) has
higher efficiency, effectiveness, and satisfaction than the other methods.
The second was: the student memorizes more information after having explored a tactile
graphic using TPad than with the traditional methods, as the learning process is not interrupted
by the consultation of the key index.
The design of the test material was done in collaboration with two teachers of the school
and using real educational material.
On the slide we can see one of the graphic used during the test.
On the left side there is the original version of the graphic,
In the middle we have a tactile graphic preview.
Where you can see the Braille labels.
On the right we have the version compatible with TPad that doesn't require Braille labels.
The user study was divided in two experiments.
In the first experiment the participant received a tactile graphic and could explore it autonomously
without time limit, but we asked the participant to be as quick and accurate as possible.
And the exploration time was recorded.
After to have explored the graphic, the participant received two questions.
To answer these two questions he could consult the tactile graphic.
A third question was given to the participant, this was a memory question, because he could
not use the graphic to answer this last question.
The procedure was repeated three times, one for each method, using three different tactile
graphics.
Considering the average exploration time the TPad system has recorded a better performance
with a statistically significant difference with both the other two methods.
Considering overall the correct answers of all participants, the two methods TPad and
Braille Key Method are similar and both with good effectiveness.
More than 70% of the correct answers.
The Digital Key Method instead did not reach satisfactory levels.
It is interesting to note that 4 out of 5 participants answered the last question correctly,
based only on their memory without to have the possibility to consult the graphic.
The three methods have a similar value for the NASA TLX index and for the System Usability
Scale.
All the participants were in favor of the TPad system, except one that expressed two
options: the TPad and the Braille Key Method.
Three students prefer TPad because they consider the system faster.
One reported that he hate to read Braille and with TPad this is not necessary.
An other participant reported that he likes that all the information was in just one place.
There are four different ways to load an audio-tactile graphic into the TPad system.
Loading a local SVG file.
Using the teacher's back-end through the remote control.
By navigating the menu with the list of the graphics in the repository, and scanning the
QR code on the back of the tactile graphic.
The second experiment was focused only on TPad and in particular we compared the last
two methods to load an audio-tactile graphic.
The QR code method was an unexpected fast strategy.
One participant was able to load a graphic in less than two seconds.
And all the participants expressed their preference for the QR code method.
Access to visual content using tactile graphics is essential for students with visual impairment
at school.
With our study, we showed that audio-tactile graphics are an effective teaching tool for
blind students.
Using TPad, the participants acquire the knowledge about a tactile graphic faster than with the
other two methods.
In our experiment, they answered correctly more than 70% of the questions.
And the possibility to focus on a single device is likely to affect positively the memory
process.
Thank you for your time.
If you have any question please contact me at giuseppe.melfi@kit.edu