Hello and welcome to this presentation
about discomfort in vr HMDs.
My name is Teresa and this is work that
was conducted by Ulm university
Telecom Paris and the university of
Stuttgart.
Feelings of discomfort or even sickness
are frequently occurring, undesired
negative side effects of VR use.
These feelings of discomfort have been
referred to with several terms, such as
simulator sickness,
visually induced motion sickness, cybersickness,
or VR sickness
and the tool that is usually used to
assess symptoms of these sicknesses
is the simulator sickness questionnaire.
The SSQ was developed in the early 90s
to study symptoms in navy pilots during
flight simulator training.
Today the SSQ is the dominant
questionnaire that is used to assess
sickness symptoms in VR settings.
However, research indicates that the SSQ
is of limited suitability as a
comprehensive measure of symptoms that
occur in VR.
Among other aspects it accounts for only
one category of symptoms and neglects
others that are nowadays more important
to consumer uses of VR technology
but weren't of that importance back when
the questionnaire was developed.
Still, the questionnaire is heavily used
in today's VR research.
To get an overview of why and how the
questionnaire is used in today's
research,
we conducted a systematic literature
review on the current practice in the
use of SSQ.
In particular, we were interested in the
author's rationales of using the
questionnaire.
We followed the PRISMA process to
identify relevant papers
and we found 309 papers that were
published in the last 11 years
after applying exclusion and inclusion
criteria.
As search term we simply applied "simulator
sickness questionnaire".
The main results of the survey are that
in only 37 percent
of the papers authors stated to use the
SSQ to assess simulator sickness
in 19 percent cyber sickness,
visually induced motion sickness, or VR
sickness were given as rationales,
and almost one third of the papers no
rationale was given or was mentioned
of why the SSQ was used.
Furthermoren in 96 percent of the papers the SSQ
was the only measure of discomfort that
was employed,
and in only 4 percent of the papers
an additional measure,
namely digital strain, was reported.
Lastly, in 39 percent of the papers no visual
vestibular conflict
conflict was present, which is known to
be the main cause of simulator sickness.
Taken together, these results indicate
that the use of the SSQ has become
common practice in VR research that the
questionnaire is often applied without
being specifically interested in
assessing simulator sickness.
Rather it seems that it is used to
assess general negative side effects
of the technology. However, as the
questionnaire covers only one category of
symptoms,
others that have increased in relevance
to users, such as digital eye strain or
symptoms caused by the headset's
ergonomics, are not covered.
However, to draw a more comprehensive
picture of discomfort in HMDs, they
should also be considered.
Therefore, in a second step we conducted
a user study to compare the prevalence
and severity of these three symptom
categories.
In the user study we asked more than 300
participants to fill out three symptom
questionnaires
after a 30-minute VR experience. We then
analyzed the symptoms using an
exploratory factor analysis.
We found six orthogonal factors of
discomfort in VR HMDs,
with one being digital eye strain, one
simulator thickness, and four addressing
specific aspects of ergonomic symptoms.
When comparing the mean symptom severity
scores of these factors,
we can see that the two most severe
factors were "perceived change" and
"sweating",
followed by "digital eye strain" and
symptoms caused by the attachment of the
device.
Simulator sickness and neck and shoulder
pain were the least severe symptoms.
Furthermore, we asked participants to
rate the relevance of each symptom
category to general discomfort by
directly comparing each two of the
categories.
We found that digital eye strain and
ergonomic symptoms
were more relevant to users than
simulated sickness.
To conclude, our key results are that it
has become common practice to use the
SSQ to assess
symptoms of VR sickness, although it
doesn't provide a comprehensive picture
of discomfort.
We therefore provide an extended factor
model of discomfort and found that
symptoms of digital eye strain and
symptoms caused by the headset's
ergonomics seem to be more
prevalent and more severe than simulator
sickness.
With this work, we aim to trigger a
discussion in the community of
rethinking discomfort in VR and its
measurements.
Furthermore, we aim to lay the
foundations for a more sensitive measure
of discomfort in VR HMDs.
Thank you very much for listening and
i'm happy to answer your questions now.