%M C.ETRA.10.11
%T An eye on input: research challenges in using the eye for computer input
control
%S Keynote address
%A MacKenzie, I. Scott
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 11-12
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743668
%X The human eye, with the assistance of an eye tracking apparatus, may serve
as an input controller to a computer system. Much like point-select operations
with a mouse, the eye can "look-select", and thereby activate items such as
buttons, icons, links, or text. Applications for accessible computing are
particularly enticing, since the manual ability of disabled users is often
lacking or limited. Whether for the able-bodied or the disabled, computer
control systems using the eye as an input "device" present numerous research
challenges. These involve accommodating the innate characteristics of the eye,
such as movement by saccades, jitter and drift in eye position, the absence of
a simple and intuitive selection method, and the inability to determine a
precise point of fixation through eye position alone.

%M C.ETRA.10.13
%T Homography normalization for robust gaze estimation in uncalibrated setups
%S Long papers 1 -- Advances in eye tracking technology
%A Hansen, Dan Witzner
%A Agustin, Javier San
%A Villanueva, Arantxa
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 13-20
%K Gaussian process, HCI, eye tracking, gaze estimation, homography
normalization, uncalibrated setup
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743670
%X Homography normalization is presented as a novel gaze estimation method for
uncalibrated setups. The method applies when head movements are present but
without any requirements to camera calibration or geometric calibration. The
method is geometrically and empirically demonstrated to be robust to head pose
changes and despite being less constrained than cross-ratio methods, it
consistently performs favorably by several degrees on both simulated data and
data from physical setups. The physical setups include the use of off-the-shelf
web cameras with infrared light (night vision) and standard cameras with and
without infrared light. The benefits of homography normalization and
uncalibrated setups in general are also demonstrated through obtaining gaze
estimates (in the visible spectrum) using only the screen reflections on the
cornea.

%M C.ETRA.10.21
%T Head-mounted eye-tracking of infants' natural interactions: a new method
%S Long papers 1 -- Advances in eye tracking technology
%A Franchak, John M.
%A Kretch, Kari S.
%A Soska, Kasey C.
%A Babcock, Jason S.
%A Adolph, Karen E.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 21-27
%K head-mounted eye-tracking, infants, natural vision
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743671
%X Currently, developmental psychologists rely on paradigms that use infants'
looking behavior as the primary measure. Despite hundreds of studies describing
infants' visual exploration of experimental stimuli, researchers know little
about where infants look during everyday interactions. Head-mounted
eye-trackers have provided many insights into natural vision in adults, but
methods and equipment that work well with adults are not suitable for infants
-- the equipment is prohibitively big and calibration procedures too demanding.
We outline the first method for studying mobile infants' visual behavior during
natural interactions. We used a new, specially designed head-mounted
eye-tracker to record 6 infants' gaze as they played with mothers in a room
full of toys and obstacles. Using this method, we measured how infants employed
gaze while navigating obstacles, manipulating objects, and interacting with
mothers. Results revealed new insights into visually guided locomotor and
manual action and social interaction.

%M C.ETRA.10.29
%T User-calibration-free remote gaze estimation system
%S Long papers 1 -- Advances in eye tracking technology
%A Model, Dmitri
%A Eizenman, Moshe
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 29-36
%K calibration free, minimal subject cooperation, point-of-gaze, remote gaze
estimation
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743672
%X Gaze estimation systems use calibration procedures that require active
subject participation to estimate the point-of-gaze accurately. In these
procedures, subjects are required to fixate on a specific point or points in
space at specific time instances. This paper describes a gaze estimation system
that does not use calibration procedures that require active user
participation. The system estimates the optical axes of both eyes using images
from a stereo pair of video cameras without a personal calibration procedure.
To estimate the point-of-gaze, which lies along the visual axis, the angles
between the optical and visual axes are estimated by a novel automatic
procedure that minimizes the distance between the intersections of the visual
axes of the left and right eyes with the surface of a display while subjects
look naturally at the display (e.g., watching a video clip). Experiments with
four subjects demonstrate that the RMS error of this point-of-gaze estimation
system is 1.3°.

%M C.ETRA.10.37
%T Eye movement as an interaction mechanism for relevance feedback in a
content-based image retrieval system
%S Short papers 1 -- Eye tracking applications and data analysis
%A Zhang, Yun
%A Fu, Hong
%A Liang, Zhen
%A Chi, Zheru
%A Feng, Dagan
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 37-40
%K content-based image retrieval (CBIR), eye tracking, relevance feedback (RF),
visual perception
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743674
%X Relevance feedback (RF) mechanisms are widely adopted in Content-Based Image
Retrieval (CBIR) systems to improve image retrieval performance. However, there
exist some intrinsic problems: (1) the semantic gap between high-level concepts
and low-level features and (2) the subjectivity of human perception of visual
contents. The primary focus of this paper is to evaluate the possibility of
inferring the relevance of images based on eye movement data. In total, 882
images from 101 categories are viewed by 10 subjects to test the usefulness of
implicit RF, where the relevance of each image is known beforehand. A set of
measures based on fixations are thoroughly evaluated which include fixation
duration, fixation count, and the number of revisits. Finally, the paper
proposes a decision tree to predict the user's input during the image searching
tasks. The prediction precision of the decision tree is over 87%, which spreads
light on a promising integration of natural eye movement into CBIR systems in
the future.

%M C.ETRA.10.41
%T Content-based image retrieval using a combination of visual features and eye
tracking data
%S Short papers 1 -- Eye tracking applications and data analysis
%A Liang, Zhen
%A Fu, Hong
%A Zhang, Yun
%A Chi, Zheru
%A Feng, Dagan
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 41-44
%K content-based image retrieval (CBIR), eye tracking, fixation, similarity
measure, visual perception
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743675
%X Image retrieval technology has been developed for more than twenty years.
However, the current image retrieval techniques cannot achieve a satisfactory
recall and precision. To improve the effectiveness and efficiency of an image
retrieval system, a novel content-based image retrieval method with a
combination of image segmentation and eye tracking data is proposed in this
paper. In the method, eye tracking data is collected by a non-intrusive table
mounted eye tracker at a sampling rate of 120 Hz, and the corresponding
fixation data is used to locate the human's Regions of Interest (hROIs) on the
segmentation result from the JSEG algorithm. The hROIs are treated as important
informative segments/objects and used in the image matching. In addition, the
relative gaze duration of each hROI is used to weigh the similarity measure for
image retrieval. The similarity measure proposed in this paper is based on a
retrieval strategy emphasizing the most important regions. Experiments on 7346
Hemera color images annotated manually show that the retrieval results from our
proposed approach compare favorably with conventional content-based image
retrieval methods, especially when the important regions are difficult to be
located based on visual features.

%M C.ETRA.10.45
%T Gaze scribing in physics problem solving
%S Short papers 1 -- Eye tracking applications and data analysis
%A Rosengrant, David
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 45-48
%K education research, gaze scribing, physics problem solving
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743676
%X Eye-tracking has been widely used for research purposes in fields such as
linguistics and marketing. However, there are many possibilities of how
eye-trackers could be used in other disciplines like physics. A part of physics
education research deals with the differences between novices and experts,
specifically how each group solves problems. Though there has been a great deal
of research about these differences there has been no research that focuses on
noticing exactly where experts and novices look while solving the problems.
Thus, to complement the past research, I have created a new technique called
gaze scribing. Subjects wear a head mounted eye-tracker while solving
electrical circuit problems on a graphics monitor. I monitor both scan patterns
of the subjects and combine that with videotapes of their work while solving
the problems. This new technique has yielded new information and elaborated on
previous studies.

%M C.ETRA.10.49
%T Have you seen any of these men?: looking at whether eyewitnesses use
scanpaths to recognize suspects in photo lineups
%S Short papers 1 -- Eye tracking applications and data analysis
%A Josephson, Sheree
%A Holmes, Michael E.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 49-52
%K eye movement, eye tracking, eyewitness identification, optimal matching
analysis, scanpath, sequence comparison, string editing
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743677
%X The repeated viewing of a suspect's face by an eyewitness during the
commission of a crime and subsequently when presented with suspects in a photo
lineup provides a real-world scenario where Noton and Stark's 1971 "scanpath
theory" of visual perception and memory can be tested. Noton and Stark defined
"scanpaths" as repetitive sequences of fixations and saccades that occur during
exposure and subsequently upon re-exposure to a visual stimulus, facilitating
recognition. Ten subjects watched a video of a staged theft in a parking lot.
Scanpaths were recorded for the initial viewing of the suspect's face and a
later close-up viewing of the suspect's face in the video, and then on the
suspect's face when his picture appeared 24 hours later in a photo lineup
constructed by law enforcement officers. These scanpaths were compared using
the string-edit methodology to measure resemblance between sequences.
Preliminary analysis showed support for repeated scanpath sub-sequences. In the
analysis of four clusters of scanpaths, there was little within-subject
resemblance between full scanpath sequences but seven of 10 subjects had
repeated scanpath sub-sequences. When a subject's multiple scanpaths across the
suspect's photo in the lineup were compared, instances of within-subjects
repetition of short scanpaths occurred more often than expected due to chance.

%M C.ETRA.10.53
%T Estimation of viewer's response for contextual understanding of tasks using
features of eye-movements
%S Short papers 1 -- Eye tracking applications and data analysis
%A Nakayama, Minoru
%A Hayashi, Yuko
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 53-56
%K answer correctness, discriminant analysis, eye-movement metrics,
eye-movements, user's response estimation
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743678
%X To estimate viewer's contextual understanding, features of their
eye-movements while viewing question statements in response to definition
statements, and features of correct and incorrect responses were extracted and
compared. Twelve directional features of eye-movements across a two-dimensional
space were created, and these features were compared between correct and
incorrect responses. The procedure of estimating the response was developed
with Support Vector Machines, using these features. The estimation performance
and accuracy were assessed across combinations of features. The number of
definition statements, which needed to be memorized to answer the question
statements during the experiment, affected the estimation accuracy. These
results provide evidence that features of eye-movements during reading
statements can be used as an index of contextual understanding.

%M C.ETRA.10.57
%T Biometric identification via an oculomotor plant mathematical model
%S Short papers 1 -- Eye tracking applications and data analysis
%A Komogortsev, Oleg V.
%A Jayarathna, Sampath
%A Aragon, Cecilia R.
%A Mahmoud, Mechehoul
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 57-60
%K biometrics, eye tracking, oculomotor plant
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743679
%X There has been increased interest in reliable, non-intrusive methods of
biometric identification due to the growing emphasis on security and increasing
prevalence of identity theft. This paper presents a new biometric approach that
involves an estimation of the unique oculomotor plant (OP) or eye globe muscle
parameters from an eye movement trace. These parameters model individual
properties of the human eye, including neuronal control signal, series
elasticity, length tension, force velocity, and active tension. These
properties can be estimated for each extraocular muscle, and have been shown to
differ between individuals. We describe the algorithms used in our approach and
the results of an experiment with 41 human subjects tracking a jumping dot on a
screen. Our results show improvement over existing eye movement biometric
identification methods. The technique of using Oculomotor Plant Mathematical
Model (OPMM) parameters to model the individual eye provides a number of
advantages for biometric identification: it includes both behavioral and
physiological human attributes, is difficult to counterfeit, non-intrusive, and
could easily be incorporated into existing biometric systems to provide an
extra layer of security.

%M C.ETRA.10.61
%T Saliency-based decision support
%S Short papers 2 -- Poster presentations
%A Canosa, Roxanne L.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 61-63
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743681
%X A model of visual saliency is often used to highlight interesting or
perceptually significant features in an image. If a specific task is imposed
upon the viewer, then the image features that disambiguate task-related objects
from non-task-related locations should be incorporated into the saliency
determination as top-down information. For this study, viewers were given the
task of locating potentially cancerous lesions in synthetically-generated
medical images. An ensemble of saliency maps was created to model the target
versus error features that attract attention. For MRI images, lesions are most
reliably modeled by luminance features and errors are mostly modeled by color
features, depending upon the type of error (search, recognition, or decision).
Other imaging modalities showed similar differences between the target and
error features that contribute to top-down saliency. This study provides
evidence that image-derived saliency is task-dependent and may be used to
predict target or error locations in complex images.

%M C.ETRA.10.65
%T Qualitative and quantitative scoring and evaluation of the eye movement
classification algorithms
%S Short papers 2 -- Poster presentations
%A Komogortsev, Oleg V.
%A Jayarathna, Sampath
%A Koh, Do Hyong
%A Gowda, Sandeep Munikrishne
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 65-68
%K algorithm, analysis, classification, eye movements, metrics, scoring
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743682
%X This paper presents a set of qualitative and quantitative scores designed to
assess performance of any eye movement classification algorithm. The scores are
designed to provide a foundation for the eye tracking researchers to
communicate about the performance validity of various eye movement
classification algorithms. The paper concentrates on the five algorithms in
particular: Velocity Threshold Identification (I-VT), Dispersion Threshold
Identification (I-DT), Minimum Spanning Tree Identification (MST), Hidden
Markov Model Identification (I-HMM) and Kalman Filter Identification (I-KF).
The paper presents an evaluation of the classification performance of each
algorithm in the case when values of the input parameters are varied.
Advantages provided by the new scores are discussed. Discussion on what is the
"best" classification algorithm is provided for several applications. General
recommendations for the selection of the input parameters for each algorithm
are provided.

%M C.ETRA.10.69
%T An interactive interface for remote administration of clinical tests based
on eye tracking
%S Short papers 2 -- Poster presentations
%A Faro, A.
%A Giordano, D.
%A Spampinato, C.
%A De Tommaso, D.
%A Ullo, S.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 69-72
%K cognitive psychology, eye tracking, medical research, neuroscience,
opthalmology, vision research
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743683
%X A challenging goal today is the use of computer networking and advanced
monitoring technologies to extend human intellectual capabilities in medical
decision making. Modern commercial eye trackers are used in many of research
fields, but the improvement of eye tracking technology, in terms of precision
on the eye movements capture, has led to consider the eye tracker as a tool for
vision analysis, so that its application in medical research, e.g. in
ophthalmology, cognitive psychology and in neuroscience has grown considerably.
The improvements of the human eye tracker interface become more and more
important to allow medical doctors to increase their diagnosis capacity,
especially if the interface allows them to remotely administer the clinical
tests more appropriate for the problem at hand. In this paper, we propose a
client/server eye tracking system that provides an interactive system for
monitoring patients eye movements depending on the clinical test administered
by the medical doctors. The system supports the retrieval of the gaze
information and provides statistics to both medical research and disease
diagnosis.

%M C.ETRA.10.73
%T Visual attention for implicit relevance feedback in a content based image
retrieval
%S Short papers 2 -- Poster presentations
%A Faro, A.
%A Giordano, D.
%A Pino, C.
%A Spampinato, C.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 73-76
%K content based image retrieval, eye tracker, relevance feedback, visual
attention
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743684
%X In this paper we propose an implicit relevance feedback method with the aim
to improve the performance of known Content Based Image Retrieval (CBIR)
systems by re-ranking the retrieved images according to users' eye gaze data.
This represents a new mechanism for implicit relevance feedback, in fact
usually the sources taken into account for image retrieval are based on the
natural behavior of the user in his/her environment estimated by analyzing
mouse and keyboard interactions. In detail, after the retrieval of the images
by querying CBIRs with a keyword, our system computes the most salient regions
(where users look with a greater interest) of the retrieved images by gathering
data from an unobtrusive eye tracker, such as Tobii T60. According to the
features, in terms of color, texture, of these relevant regions our system is
able to re-rank the images, initially, retrieved by the CBIR. Performance
evaluation, carried out on a set of 30 users by using Google Images and
"pyramid" like keyword, shows that about the 87% of the users is more satisfied
of the output images when the re-raking is applied.

%M C.ETRA.10.77
%T Evaluation of a low-cost open-source gaze tracker
%S Short papers 2 -- Poster presentations
%A Agustin, Javier San
%A Skovsgaard, Henrik
%A Mollenbach, Emilie
%A Barret, Maria
%A Tall, Martin
%A Hansen, Dan Witzner
%A Hansen, John Paulin
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 77-80
%K augmentative and alternative communication, gaze interaction, gaze typing,
low cost, off-the-shelf components
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743685
%X This paper presents a low-cost gaze tracking system that is based on a
webcam mounted close to the user's eye. The performance of the gaze tracker was
evaluated in an eye-typing task using two different typing applications.
Participants could type between 3.56 and 6.78 words per minute, depending on
the typing system used. A pilot study to assess the usability of the system was
also carried out in the home of a user with severe motor impairments. The user
successfully typed on a wall-projected interface using his eye movements.

%M C.ETRA.10.81
%T An open source eye-gaze interface: expanding the adoption of eye-gaze in
everyday applications
%S Short papers 2 -- Poster presentations
%A Hennessey, Craig
%A Duchowski, Andrew T.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 81-84
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743686
%X There is no standard software interface in the eye-tracking industry, making
it difficult for developers to integrate eye-gaze into their applications. The
combination of high cost eye-trackers and lack of applications has resulted in
a slow adoption of the technology. To expand the adoption of eye-gaze in
everyday applications, we present an eye-gaze specific application programming
interface that is platform and language neutral, based on open standards,
easily used and extended and free of cost.

%M C.ETRA.10.85
%T Using eye tracking to investigate important cues for representative creature
motion
%S Short papers 2 -- Poster presentations
%A McLendon, Meredith
%A McNamara, Ann
%A McLaughlin, Tim
%A Dwivedi, Ravindra
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 85-88
%K animation, eyetracking, perception, point-light display
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743687
%X We present an experiment designed to reveal some of the key features
necessary for conveying creature motion. Humans can reliably identify animals
shown in minimal form using Point Light Display (PLD) representations, but it
is unclear what information they use when doing so. The ultimate goal for this
research is to find recognizable traits that may be communicated to the viewer
through motion, such as size and attitude and then to use that information to
develop a new way of creating and managing animation and animation controls.
The aim of this study was to investigate whether viewers use similar visual
information when asked to identify or describe animal motion PLDs and full
representations. Participants were shown 20 videos of 10 animals, first as PLD
and then in full resolution. After each video, participants were asked to
select descriptive traits and to identify the animal represented. Species
identification results were better than chance for six of the 10 animals when
shown PLD. Results from the eye tracking show that participants' gaze was
consistently drawn to similar regions when viewing the PLD as the full
representation.

%M C.ETRA.10.89
%T Eye and pointer coordination in search and selection tasks
%S Short papers 2 -- Poster presentations
%A Bieg, Hans-Joachim
%A Chuang, Lewis L.
%A Fleming, Roland W.
%A Reiterer, Harald
%A Bülthoff, Heinrich H.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 89-92
%K eye movements, eye-hand coordination, eye-tracking, input devices,
multimodal interfaces
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743688
%X Selecting a graphical item by pointing with a computer mouse is a ubiquitous
task in many graphical user interfaces. Several techniques have been suggested
to facilitate this task, for instance, by reducing the required movement
distance. Here we measure the natural coordination of eye and mouse pointer
control across several search and selection tasks. We find that users
automatically minimize the distance to likely targets in an intelligent, task
dependent way. When target location is highly predictable, top-down knowledge
can enable users to initiate pointer movements prior to target fixation. These
findings question the utility of existing assistive pointing techniques and
suggest that alternative approaches might be more effective.

%M C.ETRA.10.93
%T Pies with EYEs: the limits of hierarchical pie menus in gaze control
%S Short papers 2 -- Poster presentations
%A Urbina, Mario H.
%A Lorenz, Maike
%A Huckauf, Anke
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 93-96
%K evaluation methodology, gaze control, input devices, marking menus, pie
menus, user interfaces
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743689
%X Pie menus offer several features which are advantageous especially for gaze
control. Although the optimal number of slices per pie and of depth layers has
already been established for manual control, these values may differ in gaze
control due to differences in spatial accuracy and cognitive processing.
Therefore, we investigated the layout limits for hierarchical pie menu in gaze
control. Our user study indicates that providing six slices in multiple depth
layers guarantees fast and accurate selections. Moreover, we compared two
different methods of selecting a slice. Novices performed well with both, but
selecting via selection borders produced better performance for experts than
the standard dwell time selection.

%M C.ETRA.10.97
%T Measuring vergence over stereoscopic video with a remote eye tracker
%S Short papers 2 -- Poster presentations
%A Daugherty, Brian C.
%A Duchowski, Andrew T.
%A House, Donald H.
%A Ramasamy, Celambarasan
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 97-100
%K eye tracking, stereoscopic rendering
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743690
%X A remote eye tracker is used to explore its utility for ocular vergence
measurement. Subsequently, vergence measurements are compared in response to
anaglyphic stereographic stimuli as well as in response to monoscopic stimulus
presentation on a standard display. Results indicate a highly significant
effect of anaglyphic stereoscopic display on ocular vergence when viewing a
stereoscopic calibration video. Significant convergence measurements were
obtained for stimuli fused in the anterior image plane.

%M C.ETRA.10.101
%T Group-wise similarity and classification of aggregate scanpaths
%S Short papers 2 -- Poster presentations
%A Grindinger, Thomas
%A Duchowski, Andrew T.
%A Sawyer, Michael
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 101-104
%K classification, eye tracking, scanpath comparison
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743691
%X We present a novel method for the measurement of the similarity between
aggregates of scanpaths. This may be thought of as a solution to the "average
scanpath" problem. As a by-product of this method, we derive a classifier for
groups of scanpaths drawn from various classes. This capability is empirically
demonstrated using data gathered from an experiment in an attempt to
automatically determine expert/novice classification for a set of visual tasks.

%M C.ETRA.10.105
%T Inferring object relevance from gaze in dynamic scenes
%S Short papers 2 -- Poster presentations
%A Kandemir, Melih
%A Saarinen, Veli-Matti
%A Kaski, Samuel
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 105-108
%K augmented reality, gaze tracking, information retrieval, intelligent user
interfaces, machine learning, ordinal logistic regression
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743692
%X As prototypes of data glasses having both data augmentation and gaze
tracking capabilities are becoming available, it is now possible to develop
proactive gaze-controlled user interfaces to display information about objects,
people, and other entities in real-world setups. In order to decide which
objects the augmented information should be about, and how saliently to
augment, the system needs an estimate of the importance or relevance of the
objects of the scene for the user at a given time. The estimates will be used
to minimize distraction of the user, and for providing efficient spatial
management of the augmented items. This work is a feasibility study on
inferring the relevance of objects in dynamic scenes from gaze. We collected
gaze data from subjects watching a video for a pre-defined task. The results
show that a simple ordinal logistic regression model gives relevance rankings
of scene objects with a promising accuracy.

%M C.ETRA.10.109
%T Advanced gaze visualizations for three-dimensional virtual environments
%S Short papers 2 -- Poster presentations
%A Stellmach, Sophie
%A Nacke, Lennart
%A Dachselt, Raimund
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 109-112
%K attentional maps, eye movements, eye tracking, gaze visualizations, scan
paths, three-dimensional, virtual environments
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743693
%X Gaze visualizations represent an effective way for gaining fast insights
into eye tracking data. Current approaches do not adequately support eye
tracking studies for three-dimensional (3D) virtual environments. Hence, we
propose a set of advanced gaze visualization techniques for supporting gaze
behavior analysis in such environments. Similar to commonly used gaze
visualizations for two-dimensional stimuli (e.g., images and websites), we
contribute advanced 3D scan paths and 3D attentional maps. In addition, we
introduce a models of interest timeline depicting viewed models, which can be
used for displaying scan paths in a selected time segment. A prototype toolkit
is also discussed which combines an implementation of our proposed techniques.
Their potential for facilitating eye tracking studies in virtual environments
was supported by a user study among eye tracking and visualization experts.

%M C.ETRA.10.113
%T The use of eye tracking for PC energy management
%S Short papers 2 -- Poster presentations
%A Moshnyaga, Vasily G.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 113-116
%K applications, energy reduction, eye tracking
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743694
%X This paper discusses a new application of eye-tracking, namely power
management, and outlines its implementation in personal computer system. Unlike
existing power management technology, which "senses" a PC user through keyboard
and/or mouse, our technology "watches" the user through a single camera. The
technology tracks the user's eyes keeping the display active only if the user
looks at the screen. Otherwise it dims the display down or even switches it off
to save energy. We implemented the technology in hardware and present the
results of its experimental evaluation.

%M C.ETRA.10.117
%T Low-latency combined eye and head tracking system for teleoperating a
robotic head in real-time
%S Short papers 2 -- Poster presentations
%A Kohlbecher, Stefan
%A Bartl, Klaus
%A Bardins, Stanislavs
%A Schneider, Erich
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 117-120
%K calibration, head-mounted, real-time
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743695
%X We have developed a low-latency combined eye and head tracker suitable for
teleoperating a remote robotic head in real-time. Eye and head movements of a
human (wizard) are tracked and replicated by the robot with a latency of 16.5
ms. The tracking is achieved by three fully synchronized cameras attached to a
head mount. One forward-looking, wide-angle camera is used to determine the
wizard's head pose with respect to the LEDs on the video monitor; the other two
cameras are for binocular eye tracking. The whole system operates at a sample
rate of 220 Hz, which allows the capture and reproduction of biological
movements as precisely as possible while keeping the overall latency low. In
future studies, this setup will be used as an experimental platform for
Wizard-of-Oz evaluations of gaze-based human-robot interaction. In particular,
the question will be addressed as to what extent aspects of human eye movements
need to be implemented in a robot in order to guarantee a smooth interaction.

%M C.ETRA.10.121
%T Visual search in the (un)real world: how head-mounted displays affect eye
movements, head movements and target detection
%S Short papers 2 -- Poster presentations
%A Kollenberg, Tobit
%A Neumann, Alexander
%A Schneider, Dorothe
%A Tews, Tessa-Karina
%A Hermann, Thomas
%A Ritter, Helge
%A Dierker, Angelika
%A Koesling, Hendrik
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 121-124
%K augmented reality, eye movements, field of view, head movements,
head-mounted display, restriction, visual search
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743696
%X Head-mounted displays (HMDs) that use a see-through display method allow for
superimposing computer-generated images upon a real-world view. Such devices,
however, normally restrict the user's field of view. Furthermore, low display
resolution and display curvature are suspected to make foveal as well as
peripheral vision more difficult and may thus affect visual processing. In
order to evaluate this assumption, we compared performance and eye-movement
patterns in a visual search paradigm under different viewing conditions:
participants either wore an HMD, had their field of view restricted by blinders
or could avail themselves of an unrestricted field of view (normal viewing).
From the head and eye-movement recordings we calculated the contribution of eye
rotation to lateral shifts of attention. Results show that wearing an HMD leads
to less eye rotation and requires more head movements than under blinders
conditions and during normal viewing.

%M C.ETRA.10.125
%T Visual span and other parameters for the generation of heatmaps
%S Short papers 2 -- Poster presentations
%A Blignaut, Pieter
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 125-128
%K eye-tracking, heatmaps, visualization
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743697
%X Although heat maps are commonly provided by eye-tracking and visualization
tools, they have some disadvantages and caution must be taken when using them
to draw conclusions on eye tracking results. It is motivated here that visual
span is an essential component of visualizations of eye-tracking data and an
algorithm is proposed to allow the analyst to set the visual span as a
parameter prior to generation of a heat map.
   Although the ideas are not novel, the algorithm also indicates how
transparency of the heat map can be achieved and how the color gradient can be
generated to represent the probability for an object to be observed within the
defined visual span. The optional addition of contour lines provides a way to
visualize separate intervals in the continuous color map.

%M C.ETRA.10.129
%T Robust optical eye detection during head movement
%S Short papers 2 -- Poster presentations
%A Mulligan, Jeffrey B.
%A Gabayan, Kevin N.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 129-132
%K active illumination, eye finding, head movement, pupil detection
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743698
%X Finding the eye(s) in an image is a critical first step in a remote
gaze-tracking system with a working volume large enough to encompass head
movements occurring during normal user behavior. We briefly review an optical
method which exploits the retroreflective properties of the eye, and present a
novel method for combining difference images to reject motion artifacts. Best
performance is obtained when a curvature operator is used to enhance punctate
features, and search is restricted to a neighborhood about the last known
location. Optimal setting of the size of this neighborhood is aided by a
statistical model of naturally-occurring head movements; we present
head-movement statistics mined from a corpus of around 800 hours of video,
collected in a team-performance experiment.

%M C.ETRA.10.133
%T What you see is where you go: testing a gaze-driven power wheelchair for
individuals with severe multiple disabilities
%S Short papers 2 -- Poster presentations
%A Wästlund, Erik
%A Sponseller, Kay
%A Pettersson, Ola
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 133-136
%K eyes-only interaction, smart wheelchair
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743699
%X Individuals with severe multiple disabilities have little or no opportunity
to express their own wishes, make choices and move independently. Because of
this, the objective of this work has been to develop a prototype for a
gaze-driven device to manoeuvre powered wheelchairs or other moving platforms.
   The prototype has the same capabilities as a normal powered wheelchair, with
two exceptions. Firstly, the prototype is controlled by eye movements instead
of by a normal joystick. Secondly, the prototype is equipped with a sensor that
stops all motion when the machine approaches an obstacle.
   The prototype has been evaluated in a preliminary clinical test with two
users. Both users clearly communicated that they appreciated and had mastered
the ability to control a powered wheelchair with their eye movements.

%M C.ETRA.10.137
%T A depth compensation method for cross-ratio based eye tracking
%S Short papers 2 -- Poster presentations
%A Coutinho, Flavio L.
%A Morimoto, Carlos H.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 137-140
%K depth compensation, depth estimation, free head motion, single camera eye
gaze tracking
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743700
%X Traditional cross-ratio methods (TCR) project a light pattern and use
invariant properties of projective geometry to estimate the gaze position.
Advantages of the TCR methods include robustness to large head movements and in
general requires just a one time per user calibration. However, the accuracy of
TCR methods decay significantly for head movements along the camera optical
axis, mainly due to the angular difference between the optical and visual axis
of the eye. In this paper we propose a depth compensation cross-ratio (DCR)
method that improves the accuracy of TCR methods for large head depth
variations. Our solution compensates the angular offset using a 2D onscreen
vector computed from a simple calibration procedure. The length of the 2D
vector, which varies with head distance, is adjusted by a scale factor that is
estimated from relative size variations of the corneal reflection pattern. The
proposed DCR solution was compared to a TCR method using synthetic and real
data from 2 users. An average improvement of 40% was observed with synthetic
data, and 8% with the real data.

%M C.ETRA.10.141
%T Estimating cognitive load using remote eye tracking in a driving simulator
%S Short papers 2 -- Poster presentations
%A Palinko, Oskar
%A Kun, Andrew L.
%A Shyrokov, Alexander
%A Heeman, Peter
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 141-144
%K cognitive load, eye tracking, pupillometry
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743701
%X We report on the results of a study in which pairs of subjects were involved
in spoken dialogues and one of the subjects also operated a simulated vehicle.
We estimated the driver's cognitive load based on pupil size measurements from
a remote eye tracker. We compared the cognitive load estimates based on the
physiological pupillometric data and driving performance data. The
physiological and performance measures show high correspondence suggesting that
remote eye tracking might provide reliable driver cognitive load estimation,
especially in simulators. We also introduced a new pupillometric cognitive load
measure that shows promise in tracking cognitive load changes on time scales of
several seconds.

%M C.ETRA.10.145
%T Small-target selection with gaze alone
%S Short papers 2 -- Poster presentations
%A Skovsgaard, Henrik
%A Mateo, Julio C.
%A Flach, John M.
%A Hansen, John Paulin
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 145-148
%K gaze interaction, universal access, zoom interfaces
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743702
%X Accessing the smallest targets in mainstream interfaces using gaze alone is
difficult, but interface tools that effectively increase the size of selectable
objects can help. In this paper, we propose a conceptual framework to organize
existing tools and guide the development of new tools. We designed a discrete
zoom tool and conducted a proof-of-concept experiment to test the potential of
the framework and the tool. Our tool was as fast as and more accurate than the
currently available two-step magnification tool. Our framework shows potential
to guide the design, development, and testing of zoom tools to facilitate the
accessibility of mainstream interfaces for gaze users.

%M C.ETRA.10.149
%T Measuring situation awareness of surgeons in laparoscopic training
%S Short papers 2 -- Poster presentations
%A Tien, Geoffrey
%A Atkins, M. Stella
%A Zheng, Bin
%A Swindells, Colin
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 149-152
%K eye tracking, situation awareness, surgery simulation
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743703
%X The study of surgeons' eye movements is an innovative way of assessing skill
and situation awareness, in that a comparison of eye movement strategies
between expert surgeons and novices may show differences that can be used in
training.
   Our preliminary study compared eye movements of 4 experts and 4 novices
performing a simulated gall bladder removal task on a dummy patient with an
audible heartbeat and simulated vital signs displayed on a secondary monitor.
We used a head-mounted Locarna PT-Mini eyetracker to record fixation locations
during the operation.
   The results showed that novices concentrated so hard on the surgical display
that they were hardly able to look at the patient's vital signs, even when
heart rate audibly changed during the procedure. In comparison, experts glanced
occasionally at the vitals monitor, thus being able to observe the patient
condition.

%M C.ETRA.10.153
%T Quantification of aesthetic viewing using eye-tracking technology: the
influence of previous training in apparel design
%S Short papers 2 -- Poster presentations
%A Park, Juyeon
%A Woods, Emily
%A DeLong, Marilyn
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 153-155
%K aesthetic response, apparel design, eye-tracking technology, previous
training
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743704
%X The purpose of this study is to explore how the viewers' previous training
is related to their aesthetic viewing in various interactions with the form and
the context, in relation to apparel design. Berlyne's two types of exploratory
behavior, diversive and specific, provided a theoretical framework to this
study. Twenty female subjects (mean age=21, SD=1.089) participated. Twenty
model images, posed by a male and a female model, were shown on an eye-tracker
screen for 10 seconds each. The findings of this study verified Berlyne's
concepts of visual exploration. One of the different findings from Berlyne's
theory was that the untrained viewers' visual attention tended to be more
significantly focused on peripheral areas of visual interest, compared to the
trained viewers, while there was no significant difference on the central,
foremost areas of visual interest between the two groups. The overall aesthetic
viewing patterns were also identified.

%M C.ETRA.10.157
%T Estimating 3D point-of-regard and visualizing gaze trajectories under
natural head movements
%S Short papers 2 -- Poster presentations
%A Takemura, Kentaro
%A Kohashi, Yuji
%A Suenaga, Tsuyoshi
%A Takamatsu, Jun
%A Ogasawara, Tsukasa
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 157-160
%K 3D point-of-regard, eye tracking, visual SLAM
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743705
%X The portability of an eye tracking system encourages us to develop a
technique for estimating 3D point-of-regard. Unlike conventional methods, which
estimate the position in the 2D image coordinates of the mounted camera, such a
technique can represent richer gaze information of the human moving in the
larger area. In this paper, we propose a method for estimating the 3D
point-of-regard and a visualization technique of gaze trajectories under
natural head movements for the head-mounted device. We employ visual SLAM
technique to estimate head configuration and extract environmental information.
Even in cases where the head moves dynamically, the proposed method could
obtain 3D point-of-regard. Additionally, gaze trajectories are appropriately
overlaid on the scene camera image.

%M C.ETRA.10.161
%T Natural scene statistics at stereo fixations
%S Short papers 2 -- Poster presentations
%A Liu, Yang
%A Cormack, Lawrence K.
%A Bovik, Alan C.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 161-164
%K fixation, natural scene statistics, stereopsis
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743706
%X We conducted eye tracking experiments on naturalistic stereo images
presented through a haploscope, and found that fixated luminance contrast and
luminance gradient were generally higher than randomly selected luminance
contrast and luminance gradient, which agrees with previous literatures.
However we also found that the fixated disparity contrast and disparity
gradient were generally lower than randomly selected disparity contrast and
disparity gradient. We discuss the implications of this remarkable result.

%M C.ETRA.10.165
%T Development of eye-tracking pen display based on stereo bright pupil
technique
%S Short papers 2 -- Poster presentations
%A Yamamoto, Michiya
%A Nagamatsu, Takashi
%A Watanabe, Tomio
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 165-168
%K bright pupil technique, embodied interaction, eye-tracking, pen display
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743707
%X The intuitive user interfaces of PCs and PDAs, such as pen display and touch
panel, have become widely used in recent times. In this study, we have
developed an eye-tracking pen display based on the stereo bright pupil
technique. First, the bright pupil camera was developed by examining the
arrangement of cameras and LEDs for pen display. Next, the gaze estimation
method was proposed for the stereo bright pupil camera, which enables one point
calibration. Then, the prototype of the eye-tracking pen display was developed.
The accuracy of the system was approximately 0.7° on average, which is
sufficient for human interaction support. We also developed an eye-tracking
tabletop as an application of the proposed stereo bright pupil technique.

%M C.ETRA.10.169
%T Pupil center detection in low resolution images
%S Short papers 2 -- Poster presentations
%A Droege, Detlev
%A Paulus, Dietrich
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 169-172
%K gaze tracking, low resolution, pupil center detection
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743708
%X In some situations, high quality eye tracking systems are not affordable.
This generates the demand for inexpensive systems built upon non-specialized,
off the shelf devices. Investigations show that algorithms developed for high
resolution systems do not perform satisfactorily on such lowcost and low
resolution systems. We investigate algorithms specifically tailored to such low
resolution input devices, based on combinations of different strategies. An
approach called gradient direction consensus is introduced and compared to
image based correlation with adaptive templates as well as other known methods.
The results are compared using synthetic input data with known ground truth.

%M C.ETRA.10.173
%T Using vision and voice to create a multimodal interface for Microsoft Word
2007
%S Short papers 2 -- Poster presentations
%A Beelders, T. R.
%A Blignaut, P. J.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 173-176
%K eye-tracking, multimodal, speech recognition, usability, word processing
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743709
%X There has recently been a call to move away from the standard WIMP type of
interfaces and give users access to more intuitive interaction techniques.
Therefore, it in order to test the usability of a multimodal interface in Word
2007, the most popular word processor, the additional modalities of eye gaze
and speech recognition were added within Word 2007 as interaction techniques.
This paper discusses the developed application and the way in which the
interaction techniques are included within the well-established environment of
Word 2007. The additional interaction techniques are fully customizable and can
be used in isolation or in combination. Eye gaze can be used with dwell time,
look and shoot or blinking and speech recognition can be used for dictation and
verbal commands for both formatting purposes and navigation through a document.
Additionally, the look and shoot method can also be combined with a verbal
command to facilitate a completely hands-free interaction. Magnification of the
interface is also provided to improve accuracy and multiple onscreen keyboards
are provided to provide hands free typing capabilities.

%M C.ETRA.10.177
%T Single gaze gestures
%S Short papers 2 -- Poster presentations
%A Møllenbach, Emilie
%A Lillholm, Martin
%A Gail, Alastair
%A Hansen, John Paulin
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 177-180
%K gaze gestures, gaze interaction, interaction design
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743710
%X This paper examines gaze gestures and their applicability as a generic
selection method for gaze-only controlled interfaces. The method explored here
is the Single Gaze Gesture (SGG), i.e. gestures consisting of a single
point-to-point eye movement. Horizontal and vertical, long and short SGGs were
evaluated on two eye tracking devices (Tobii/QuickGlance (QG)). The main
findings show that there is a significant difference in selection times between
long and short SGGs, between vertical and horizontal selections, as well as
between the different tracking systems.

%M C.ETRA.10.181
%T Learning relevant eye movement feature spaces across users
%S Short papers 2 -- Poster presentations
%A Hussain, Zakria
%A Pasupa, Kitsuchart
%A Shawe-Taylor, John
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 181-185
%K Nyström method, Tobii eye tracker, eye movement features, feature
selection, online learning
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743711
%X In this paper we predict the relevance of images based on a low-dimensional
feature space found using several users' eye movements. Each user is given an
image-based search task, during which their eye movements are extracted using a
Tobii eye tracker. The users also provide us with explicit feedback regarding
the relevance of images. We demonstrate that by using a greedy Nyström
algorithm on the eye movement features of different users, we can find a
suitable low-dimensional feature space for learning. We validate the
suitability of this feature space by projecting the eye movement features of a
new user into this space, training an online learning algorithm using these
features, and showing that the number of mistakes (regret over time) made in
predicting relevant images is lower than when using the original eye movement
features. We also plot Recall-Precision and ROC curves, and use a sign test to
verify the statistical significance of our results.

%M C.ETRA.10.187
%T Towards task-independent person authentication using eye movement signals
%S Short papers 2 -- Poster presentations
%A Kinnunen, Tomi
%A Sedlak, Filip
%A Bednarik, Roman
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 187-190
%K biometrics, eye tracking, task independence
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743712
%X We propose a person authentication system using eye movement signals. In
security scenarios, eye-tracking has earlier been used for gaze-based password
entry. A few authors have also used physical features of eye movement signals
for authentication in a task-dependent scenario with matched training and test
samples. We propose and implement a task-independent scenario whereby the
training and test samples can be arbitrary. We use short-term eye gaze
direction to construct feature vectors which are modeled using Gaussian
mixtures. The results suggest that there are personspecific features in the eye
movements that can be modeled in a task-independent manner. The range of
possible applications extends beyond the security-type of authentication to
proactive and user-convenience systems.

%M C.ETRA.10.191
%T Gaze-based web search: the impact of interface design on search result
selection
%S Short papers 2 -- Poster presentations
%A Kammerer, Yvonne
%A Beinhauer, Wolfgang
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 191-194
%K gaze-based interaction, input devices, search result selection, search
results interfaces, web search
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743713
%X This paper presents a study which examined the selection of Web search
results with a gaze-based input device. A standard list interface was compared
to a grid and a tabular layout with regard to task performance and subjective
ratings. Furthermore, the gaze-based input device was compared to conventional
mouse interaction. Test persons had to accomplish a series of search tasks by
selecting search results. The study revealed that mouse users accomplished more
tasks correctly than users of the gaze-based input device. However, no
differences were found between input devices regarding the number of search
results taken into account to accomplish a task. Regarding task completion time
and ease of search result selection only in the list interface gaze-based
interaction was inferior to mouse interaction. Moreover, with a gaze-based
input device search tasks were accomplished faster in tabular presentation than
in a standard list interface, suggesting a tabular interface as best suited for
gaze-based interaction.

%M C.ETRA.10.195
%T Eye tracking with the adaptive optics scanning laser ophthalmoscope
%S Short papers 2 -- Poster presentations
%A Stevenson, Scott B.
%A Roorda, Austin
%A Kumar, Girish
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 195-198
%K eye tracking technologies, ocular tremor, retinal imaging
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743714
%X Recent advances in high magnification retinal imaging have allowed for
visualization of individual retinal photoreceptors, but these systems also
suffer from distortions due to fixational eye motion. Algorithms developed to
remove these distortions have the added benefit of providing arc second level
resolution of the eye movements that produce them. The system also allows for
visualization of targets on the retina, allowing for absolute retinal position
measures to the level of individual cones. This paper will describe the process
used to remove the eye movement artifacts and present analysis of their
spectral characteristics. We find a roughly 1/f amplitude spectrum similar to
that reported by Findlay (1971) with no evidence for a distinct tremor
component.

%M C.ETRA.10.199
%T Listing's and Donders' laws and the estimation of the point-of-gaze
%S Short papers 2 -- Poster presentations
%A Guestrin, Elias D.
%A Eizenman, Moshe
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 199-202
%K Donders' law, Listing's law, eye torsion, gaze estimation accuracy,
kinematics of the eye
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743715
%X This paper examines the use of Listing's and Donders' laws for the
calculation of the torsion of the eye in the estimation of the point-of-gaze.
After describing Listing's and Donders' laws and providing their analytical
representation, experimental results obtained while subjects looked at a
computer screen are presented. The experimental results show that when the
point-of-gaze was estimated using Listing's and Donders' laws there was no
significant accuracy improvement relative to when eye torsion was ignored.
While for a larger range of eye rotation the torsion would be more significant
and should be taken into account, the torsion predicted by Listing's and
Donders' laws may be inaccurate, even in ideal conditions. Moreover, eye
torsion resulting from lateral head tilt can be significantly larger than the
torsion predicted by Listing's and Donders' laws, and even have opposite
direction. To properly account for eye torsion, it should be measured
independently (e.g., by tracking the iris pattern and/or the scleral blood
vessels).

%M C.ETRA.10.203
%T Visual scanpath representation
%S Long papers 2 -- Scanpath representation and comparison methods
%A Goldberg, Joseph H.
%A Helfman, Jonathan I.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 203-210
%K eye tracking, scanning strategy, scanpath, usability evaluation,
visualization
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743717
%X Eye tracking scanpaths contain information about how people see, but
traditional tangled, overlapping scanpath representations provide little
insight about scanning strategies. The present work describes and extends
several compact visual scanpath representations that can provide additional
insight about individual and aggregate/multiple scanning strategies. Three
categories of representations are introduced: (1) Scaled traces are small
images of scanpaths as connected saccades, allowing the comparison of relative
fixation densities and distributions of saccades. (2) Time expansions,
substituting ordinal position for either the scanpath's x or y-coordinates, can
uncover otherwise subtle horizontal or vertical reversals in visual scanning.
(3) Radial plots represent scanpaths as a set of radial arms about an origin,
with each arm representing saccade counts or lengths within a binned set of
absolute or relative angles. Radial plots can convey useful shape
characteristics of scanpaths, and can provide a basis for new metrics. Nine
different prototype scanning strategies were represented by these plots, then
heuristics were developed to classify the major strategies. The heuristics were
subsequently applied to real scanpath data, to identify strategy trends. Future
work will further automate the identification of scanning strategies to provide
researchers with a tool to uncover and diagnose scanning-related challenges.

%M C.ETRA.10.211
%T A vector-based, multidimensional scanpath similarity measure
%S Long papers 2 -- Scanpath representation and comparison methods
%A Jarodzka, Halszka
%A Holmqvist, Kenneth
%A Nyström, Marcus
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 211-218
%K Levenshtein distance, scanpath, sequence analysis, string edit, vector
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743718
%X A great need exists in many fields of eye-tracking research for a robust and
general method for scanpath comparisons. Current measures either quantize
scanpaths in space (string editing measures like the Levenshtein distance) or
in time (measures based on attention maps). This paper proposes a new pairwise
scanpath similarity measure. Unlike previous measures that either use AOI
sequences or forgo temporal order, the new measure defines scanpaths as a
series of geometric vectors and compares temporally aligned scanpaths across
several dimensions: shape, fixation position, length, direction, and fixation
duration. This approach offers more multifaceted insights to how similar two
scanpaths are. Eight fictitious scanpath pairs are tested to elucidate the
strengths of the new measure, both in itself and compared to two of the
currently most popular measures -- the Levenshtein distance and attention map
correlation.

%M C.ETRA.10.219
%T Scanpath comparison revisited
%S Long papers 2 -- Scanpath representation and comparison methods
%A Duchowski, Andrew T.
%A Driver, Jason
%A Jolaoso, Sheriff
%A Tan, William
%A Ramey, Beverly N.
%A Robbins, Ami
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 219-226
%K eye tracking, scanpath comparison
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743719
%X The scanpath comparison framework based on string editing is revisited. The
previous method of clustering based on k-means "preevaluation" is replaced by
the mean shift algorithm followed by elliptical modeling via Principal
Components Analysis. Ellipse intersection determines cluster overlap, with fast
nearest-neighbor search provided by the kd-tree. Subsequent construction of Y
-- matrices and parsing diagrams is fully automated, obviating prior
interactive steps. Empirical validation is performed via analysis of eye
movements collected during a variant of the Trail Making Test, where
participants were asked to visually connect alphanumeric targets (letters and
numbers). The observed repetitive position similarity index matches previously
published results, providing ongoing support for the scanpath theory (at least
in this situation). Task dependence of eye movements may be indicated by the
global position index, which differs considerably from past results based on
free viewing.

%M C.ETRA.10.227
%T Scanpath clustering and aggregation
%S Long papers 3 -- Analysis and interpretation of eye movements
%A Goldberg, Joseph H.
%A Helfman, Jonathan I.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 227-234
%K dotplot, eye tracking, pattern analysis, sequence analysis, sequential
clustering, string analysis, usability evaluation
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743721
%X Eye tracking specialists often need to understand and represent aggregate
scanning strategies, but methods to identify similar scanpaths and aggregate
multiple scanpaths have been elusive. A new method is proposed here to identify
scanning strategies by aggregating groups of matching scanpaths automatically.
A dataset of scanpaths is first converted to sequences of viewed area names,
which are then represented in a dotplot. Matching sequences in the dotplot are
found with linear regressions, and then used to cluster the scanpaths
hierarchically. Aggregate scanning strategies are generated for each cluster
and presented in an interactive dendrogram. While the clustering and
aggregation method works in a bottom-up fashion, based on pair-wise matches, a
top-down extension is also described, in which a scanning strategy is first
input by cursor gesture, then matched against the dataset. The ability to
discover both bottom-up and top-down strategy matches provides a powerful tool
for scanpath analysis, and for understanding group scanning strategies.

%M C.ETRA.10.235
%T Match-moving for area-based analysis of eye movements in natural tasks
%S Long papers 3 -- Analysis and interpretation of eye movements
%A Ryan, Wayne J.
%A Duchowski, Andrew T.
%A Vincent, Ellen A.
%A Battisto, Dina
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 235-242
%K eye tracking, match moving
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743722
%X Analysis of recordings made by a wearable eye tracker is complicated by
video stream synchronization, pupil coordinate mapping, eye movement analysis,
and tracking of dynamic Areas Of Interest (AOIs) within the scene. In this
paper a semi-automatic system is developed to help automate these processes.
Synchronization is accomplished via side by side video playback control. A
deformable eye template and calibration dot marker allow reliable
initialization via simple drag and drop as well as a user-friendly way to
correct the algorithm when it fails. Specifically, drift may be corrected by
nudging the detected pupil center to the appropriate coordinates. In a case
study, the impact of surrogate nature views on physiological health and
perceived well-being is examined via analysis of gaze over images of nature. A
match-moving methodology was developed to track AOIs for this particular
application but is applicable toward similar future studies.

%M C.ETRA.10.243
%T Interpretation of geometric shapes: an eye movement study
%S Long papers 3 -- Analysis and interpretation of eye movements
%A Prats, Miquel
%A Garner, Steve
%A Jowers, Iestyn
%A McKay, Alison
%A Pedreira, Nieves
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 243-250
%K design, eye tracking, shape perception
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743723
%X This paper describes a study that seeks to explore the correlation between
eye movements and the interpretation of geometric shapes. This study is
intended to inform the development of an eye tracking interface for
computational tools to support and enhance the natural interaction required in
creative design.
   A common criticism of computational design tools is that they do not enable
manipulation of designed shapes according to all perceived features. Instead
the manipulations afforded are limited by formal structures of shapes. This
research examines the potential for eye movement data to be used to recognise
and make available for manipulation the perceived features in shapes.
   The objective of this study was to analyse eye movement data with the
intention of recognising moments in which an interpretation of shape is made.
Results suggest that fixation duration and saccade amplitude prove to be
consistent indicators of shape interpretation.

%M C.ETRA.10.251
%T User-calibration-free gaze tracking with estimation of the horizontal angles
between the visual and the optical axes of both eyes
%S Short papers 3 -- Advances in eye tracking technology
%A Nagamatsu, Takashi
%A Sugano, Ryuichi
%A Iwamoto, Yukina
%A Kamahara, Junzo
%A Tanaka, Naoki
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 251-254
%K calibration-free, eye model, eye movement, gaze tracking
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743725
%X This paper presents a user-calibration-free method for estimating the point
of gaze (POG) on a display accurately with estimation of the horizontal angles
between the visual and the optical axes of both eyes. By using one pair of
cameras and two light sources, the optical axis of the eye can be estimated.
This estimation is carried out by using a spherical model of the cornea. The
point of intersection of the optical axis of the eye with the display is termed
POA. By detecting the POAs of both the eyes, the POG is approximately estimated
as the midpoint of the line joining the POAs of both the eyes on the basis of
the binocular eye model; therefore, we can estimate the horizontal angles
between the visual and the optical axes of both the eyes without requiring user
calibration. We have developed a prototype system based on this method using a
19" display with two pairs of stereo cameras. We evaluated the system
experimentally with 20 subjects who were at a distance of 600 mm from the
display. The result shows that the average of the root-mean-square error (RMSE)
of measurement of POG in the display screen coordinate system is 16.55 mm
(equivalent to less than 1.58°).

%M C.ETRA.10.255
%T Gaze estimation method based on an aspherical model of the cornea: surface
of revolution about the optical axis of the eye
%S Short papers 3 -- Advances in eye tracking technology
%A Nagamatsu, Takashi
%A Iwamoto, Yukina
%A Kamahara, Junzo
%A Tanaka, Naoki
%A Yamamoto, Michiya
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 255-258
%K calibration-free, eye model, eye movement, gaze tracking
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743726
%X A novel gaze estimation method based on a novel aspherical model of the
cornea is proposed in this paper. The model is a surface of revolution about
the optical axis of the eye. The calculation method is explained on the basis
of the model. A prototype system for estimating the point of gaze (POG) has
been developed using this method. The proposed method has been found to be more
accurate than the gaze estimation method based on a spherical model of the
cornea.

%M C.ETRA.10.259
%T The pupillometric precision of a remote video eye tracker
%S Short papers 3 -- Advances in eye tracking technology
%A Klingner, Jeff
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 259-262
%K eye tracking, metrology, pupil, pupillometry
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743727
%X To determine the accuracy and precision of pupil measurements made with the
Tobii 1750 remote video eye tracker, we performed a formal metrological study
with respect to a calibrated reference instrument, a medical pupillometer. We
found that the eye tracker measures mean binocular pupil diameter with
precision 0.10 mm and mean binocular pupil dilations with precision 0.15 mm.

%M C.ETRA.10.263
%T Contingency evaluation of gaze-contingent displays for real-time visual
field simulations
%S Short papers 3 -- Advances in eye tracking technology
%A Vinnikov, Margarita
%A Allison, Robert S.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 263-266
%K contingency evaluation, display, gaze contingent, head-eye tracking system
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743728
%X The visual field is the area of space that can be seen when an observer
fixates a given point. Many visual capabilities vary with position in the
visual field and many diseases result in changes in the visual field. With
current technology, it is possible to build very complex real-time visual field
simulations that employ gaze-contingent displays. Nevertheless, there are still
no established techniques to evaluate such systems. We have developed a method
to evaluate a system's contingency by employing visual blind spot localization
as well as foveal fixation. During the experiment, gaze-contingent and static
conditions were compared. There was a strong correlation between predicted
results and gaze-contingent trials. This evaluation method can also be used
with patient populations and for the evaluation of gaze-contingent display
systems, when there is need to evaluate a visual field outside of the foveal
region.

%M C.ETRA.10.267
%T SemantiCode: using content similarity and database-driven matching to code
wearable eyetracker gaze data
%S Short papers 3 -- Advances in eye tracking technology
%A Pontillo, Daniel F.
%A Kinsman, Thomas B.
%A Pelz, Jeff B.
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 267-270
%K eyetracking, gaze data analysis, semantic coding
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743729
%X Laboratory eyetrackers, constrained to a fixed display and static (or
accurately tracked) observer, facilitate automated analysis of fixation data.
Development of wearable eyetrackers has extended environments and tasks that
can be studied at the expense of automated analysis.
   Wearable eyetrackers provide 2D point-of-regard (POR) in scene-camera
coordinates, but the researcher is typically interested in some high-level
semantic property (e.g., object identity, region, or material) surrounding
individual fixation points. The synthesis of POR into fixations and semantic
information remains a labor-intensive manual task, limiting the application of
wearable eyetracking.
   We describe a system that segments POR videos into fixations and allows
users to train a database-driven, object-recognition system. A correctly
trained library results in a very accurate and semi-automated translation of
raw POR data into a sequence of objects, regions or materials.

%M C.ETRA.10.271
%T Context switching for fast key selection in text entry applications
%S Short papers 3 -- Advances in eye tracking technology
%A Morimoto, Carlos H.
%A Amir, Arnon
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 271-274
%K context switching, gaze interfaces, gaze typing
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743730
%X This paper presents context switching as an alternative to selection by
dwell time. The technique trades screen space for comfort and speed. By
replicating the interface on two separate regions called contexts, the user can
comfortably explore the whole content of a context without the effects of the
Midas touch problem. Focus within a context is set by a short dwell time and
fast selection is done by switching contexts. We present experimental results
for a text entry application with 7 participants that show significant speed
improvement over traditional fixed dwell time gaze controlled keyboards. After
8 sessions, 6 participants were able to type about 12 words per minute (wpm),
and the fastest participant was able to type above 20 wpm with error rate under
2%.

%M C.ETRA.10.275
%T Fixation-aligned pupillary response averaging
%S Long papers 4 -- Analysis and understanding of visual tasks
%A Klingner, Jeff
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 275-282
%K eye tracking, fixation, fixation-aligned pupillary response, pupillometry,
scan path, task-evoked pupillary response
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743732
%X We propose a new way of analyzing pupil measurements made in conjunction
with eye tracking: fixation-aligned pupillary response averaging, in which
short windows of continuous pupil measurements are selected based on patterns
in eye tracking data, temporally aligned, and averaged together. Such short
pupil data epochs can be selected based on fixations on a particular spot or a
scan path. The windows of pupil data thus selected are aligned by temporal
translation and linear warping to place corresponding parts of the gaze
patterns at corresponding times and then averaged together. This approach
enables the measurement of quick changes in cognitive load during visual tasks,
in which task components occur at unpredictable times but are identifiable via
gaze data. We illustrate the method through example analyses of visual search
and map reading. We conclude with a discussion of the scope and limitations of
this new method.

%M C.ETRA.10.283
%T Understanding the benefits of gaze enhanced visual search
%S Long papers 4 -- Analysis and understanding of visual tasks
%A Qvarfordt, Pernilla
%A Biehl, Jacob T.
%A Golovchinsky, Gene
%A Dunningan, Tony
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 283-290
%K gaze-enhanced visual search, multiple targets, two-phase search
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743733
%X In certain applications such as radiology and imagery analysis, it is
important to minimize errors. In this paper we evaluate a structured inspection
method that uses eye tracking information as a feedback mechanism to the image
inspector. Our two-phase method starts with a free viewing phase during which
gaze data is collected. During the next phase, we either segment the image,
mask previously seen areas of the image, or combine the two techniques, and
repeat the search. We compare the different methods proposed for the second
search phase by evaluating the inspection method using true positive and false
negative rates, and subjective workload. Results show that gaze-blocked
configurations reduced the subjective workload, and that gaze-blocking without
segmentation showed the largest increase in true positive identifications and
the largest decrease in false negative identifications of previously unseen
objects.

%M C.ETRA.10.291
%T Image ranking with implicit feedback from eye movements
%S Long papers 4 -- Analysis and understanding of visual tasks
%A Hardoon, David R.
%A Pasupa, Kitsuchart
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 291-298
%K image retrieval, implicit feedback, ranking, support vector machine, tensor
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743734
%X In order to help users navigate an image search system, one could provide
explicit information on a small set of images as to which of them are relevant
or not to their task. These rankings are learned in order to present a user
with a new set of images that are relevant to their task. Requiring such
explicit information may not be feasible in a number of cases, we consider the
setting where the user provides implicit feedback, eye movements, to assist
when performing such a task. This paper explores the idea of implicitly
incorporating eye movement features in an image ranking task where only images
are available during testing. Previous work had demonstrated that combining eye
movement and image features improved on the retrieval accuracy when compared to
using each of the sources independently. Despite these encouraging results the
proposed approach is unrealistic as no eye movements will be presented a-priori
for new images (i.e. only after the ranked images are presented would one be
able to measure a user's eye movements on them). We propose a novel search
methodology which combines image features together with implicit feedback from
users' eye movements in a tensor ranking Support Vector Machine and show that
it is possible to extract the individual source-specific weight vectors.
Furthermore, we demonstrate that the decomposed image weight vector is able to
construct a new image-based semantic space that outperforms the retrieval
accuracy than when solely using the image-features.

%M C.ETRA.10.299
%T How the interface design influences users' spontaneous trustworthiness
evaluations of web search results: comparing a list and a grid interface
%S Long papers 5 -- Gaze interfaces and interactions
%A Kammerer, Yvonne
%A Gerjets, Peter
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 299-306
%K WWW search, evaluation processes, eye tracking methodology, search engines,
search results interface, trustworthiness, viewing sequences
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743736
%X This study examined to what extent users spontaneously evaluate the
trustworthiness of Web search results presented by a search engine. For this
purpose, a methodological paradigm was used in which the trustworthiness order
of search results was experimentally manipulated by presenting search results
on a search engine results page (SERP) either in a descending or ascending
trustworthiness order. Moreover, a standard list format was compared to a grid
format in order to examine the impact of the search results interface on Web
users' evaluation processes. In an experiment addressing a controversial
medical topic, 80 participants were assigned to one of four conditions with
trustworthiness order (descending vs. ascending) and search results interface
(list vs. grid) varied as between-subjects factors. In order to investigate
participants' evaluation processes their eye movements and mouse clicks were
captured during Web search. Results revealed that a list interface caused more
homogenous and more linear viewing sequences on SERPs than a grid interface.
Furthermore, when using a list interface most attention was given to the search
results on top of the list. In contrast, with a grid interface nearly all
search results on a SERP were attended to equivalently long. Consequently, in
the ascending trustworthiness order participants using a list interface
attended significantly longer to the least trustworthy search results and
selected the most trustworthy search results significantly less often than
participants using a grid interface. Thus, the presentation of Web search
results by means of a grid interface seems to support users in their selection
of trustworthy information sources.

%M C.ETRA.10.307
%T Space-variant spatio-temporal filtering of video for gaze visualization and
perceptual learning
%S Long papers 5 -- Gaze interfaces and interactions
%A Dorr, Michael
%A Jarodzka, Halszka
%A Barth, Erhardt
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 307-314
%K gaze visualization, perceptual learning, space-variant filtering,
spatiotemporal Laplacian pyramid
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743737
%X We introduce an algorithm for space-variant filtering of video based on a
spatio-temporal Laplacian pyramid and use this algorithm to render videos in
order to visualize prerecorded eye movements. Spatio-temporal contrast and
colour saturation are reduced as a function of distance to the nearest gaze
point of regard, i.e. non-fixated, distracting regions are filtered out,
whereas fixated image regions remain unchanged. Results of an experiment in
which the eye movements of an expert on instructional videos are visualized
with this algorithm, so that the gaze of novices is guided to relevant image
locations, show that this visualization technique facilitates the novices'
perceptual learning.

%M C.ETRA.10.315
%T Alternatives to single character entry and dwell time selection on eye
typing
%S Long papers 5 -- Gaze interfaces and interactions
%A Urbina, Mario H.
%A Huckauf, Anke
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 315-322
%K eye tracking, eye-typing, gaze control, input devices, longitudinal study,
selection methods, user interfaces
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743738
%X Eye typing could provide motor disabled people a reliable method of
communication given that the text entry speed of current interfaces can be
increased to allow for fluent communication. There are two reasons for the
relatively slow text entry: dwell time selection requires waiting a certain
time, and single character entry limits the maximum entry speed. We adopted a
typing interface based on hierarchical pie menus, pEYEwrite [Urbina and Huckauf
2007] and included bigram text entry with one single pie iteration. Therefore,
we introduced three different bigram building strategies. Moreover, we combined
dwell time selection with selection by borders, providing an alternative
selection method and extra functionality. In a longitudinal study we compared
participants performance during character-by-character text entry with bigram
entry and with text entry with bigrams derived by word prediction. Data showed
large advantages of the new entry methods over single character text entry in
speed and accuracy. Participants preferred selecting by borders, which allowed
them faster selections than the dwell time method.

%M C.ETRA.10.323
%T Designing gaze gestures for gaming: an investigation of performance
%S Long papers 6 -- Eye tracking and accessibility
%A Istance, Howell
%A Hyrskykari, Aulikki
%A Immonen, Lauri
%A Mansikkamaa, Santtu
%A Vickers, Stephen
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 323-330
%K eye tracking, feedback, gaze and gaming, gaze control, gaze gestures
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743740
%X To enable people with motor impairments to use gaze control to play online
games and take part in virtual communities, new interaction techniques are
needed that overcome the limitations of dwell clicking on icons in the games
interface. We have investigated gaze gestures as a means of achieving this. We
report the results of an experiment with 24 participants that examined
performance differences between different gestures. We were able to predict the
effect on performance of the numbers of legs in the gesture and the primary
direction of eye movement in a gesture. We also report the outcomes of user
trials in which 12 experienced gamers used the gaze gesture interface to play
World of Warcraft. All participants were able to move around and engage other
characters in fighting episodes successfully. Gestures were good for issuing
specific commands such as spell casting, and less good for continuous control
of movement compared with other gaze interaction techniques we have developed.

%M C.ETRA.10.331
%T ceCursor, a contextual eye cursor for general pointing in windows
environments
%S Long papers 6 -- Eye tracking and accessibility
%A Porta, Marco
%A Ravarelli, Alice
%A Spagnoli, Giovanni
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 331-337
%K alternative communication, assistive technology, eye cursor, eye pointing,
eye tracking, gaze interaction
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743741
%X Eye gaze interaction for disabled people is often dealt with by designing
ad-hoc interfaces, in which the big size of their elements compensates for both
the inaccuracy of eye trackers and the instability of the human eye. Unless
solutions for reliable eye cursor control are employed, gaze pointing in
ordinary graphical operating environments is a very difficult task. In this
paper we present an eye-driven cursor for MS Windows which behaves differently
according to the "context". When the user's gaze is perceived within the
desktop or a folder, the cursor can be discretely shifted from one icon to
another. Within an application window or where there are no icons, on the
contrary, the cursor can be continuously and precisely moved. Shifts in the
four directions (up, down, left, right) occur through dedicated buttons. To
increase user awareness of the currently pointed spot on the screen while
continuously moving the cursor, a replica of the spot is provided within the
active direction button, resulting in improved pointing performance.

%M C.ETRA.10.339
%T BlinkWrite2: an improved text entry method using eye blinks
%S Long papers 6 -- Eye tracking and accessibility
%A Ashtiani, Behrooz
%A MacKenzie, I. Scott
%B Proceedings of the 2010 Symposium on Eye Tracking Research &
Applications
%D 2010-03-22
%P 339-345
%K alternative communication, assistive technologies, blink detection, blink
input, blink typing, eye typing, hands free text-entry, locked-in syndrome,
scanning ambiguous keyboard, single input modality
%* (c) Copyright 2010 ACM
%W http://doi.acm.org/10.1145/1743666.1743742
%X Areas of design improvements for BlinkWrite, an eye blink text entry system,
are examined, implemented, and evaluated. The result, BlinkWrite2, is a text
entry system for individuals with severe motor impairment. Since the ability to
blink is often preserved, even in severe conditions such as locked-in syndrome,
BlinkWrite2 allows text entry and correction with blinks as the only input
modality. Advantages of BlinkWrite2 over its predecessor include an increase in
text entry speed. In a user evaluation, 12 participants achieved an average
text entry rate of 5.3 wpm, representing a 16% increase over BlinkWrite and a
657% increase over the next fastest video-based eye blink text entry system
reported in the literature.