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7
Usability of a Multimodal Video Game
to Improve Navigation Skills
for Blind Children
JAIME S ´
ANCHEZ and MAURICIO SAENZ
University of Chile
and
JOSE MIGUEL GARRIDO
Pontifical Catholic University of Valpara´ıso
This work presents an evaluative study on the usability of a haptic device together with a sound-
based video game for the development and use of orientation and mobility (O&M) skills in closed,
unfamiliar spaces by blind, school-aged children. A usability evaluation was implemented for
a haptic device especially designed for this study (Digital Clock Carpet) and a 3D video game
(MOVA3D) in order to determine the degree to which the user accepted the device, and the level
of the user’s satisfaction regarding her interaction with these products for O&M purposes. In
addition, a cognitive evaluation was administered. The results show that both the haptic device
and the video game are usable, accepted and considered to be pleasant for use by blind children.
The results also show that they are ready to be used for cognitive learning purposes. Results
from a cognitive study demonstrated significant gains in tempo-spatial orientation skills of blind
children when navigating in unfamiliar spaces.
Categories and Subject Descriptors: K.4.2 [Computers and Society]: Social Issues—Assistive
technologies for persons with disabilities
General Terms: Human Factors
Additional Key Words and Phrases: Blind children, virtual environments, navigation, haptic and
audio interfaces
ACM Reference Format:
S´anchez, J., Saenz, M., and Garrido, J. M. 2010. Usability of a multimodal video game to improve
navigation skills for blind children. ACM Trans. Access. Comput. 3, 2, Article 7 (November 2010),
29 pages. DOI = 10.1145/1857920.1857924. http://doi.acm.org/10.1145/1857920.1857924.
This article was funded by the Chilean National Fund of Science and Technology, Fondecyt
#1090352 and Project CIE-05 Program Center Education PBCT-Conicyt.
Authors’ addresses: J. S´anchez, Department of Computer Science, Center for Advanced Research
in Education (CARE), University of Chile; email: jsanchez@dcc.uchile.cl; M. Saenz, Department of
Computer Science, Center for Advanced Research in Education (CARE), University of Chile; email:
msaenz@dcc.uchile.cl; J. M. Garrido, Enlaces, School of Pedagogy, Pontifical Catholic University of
Val p a r a´ıso; email: jgarrido@ucv.cl.
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c
2010 ACM 1936-7228/2010/11-ART7 $10.00 DOI: 10.1145/1857920.1857924.
http://doi.acm.org/10.1145/1857920.1857924.
ACM Transactions on Accessible Computing, Vol. 3, No. 2, Article 7, Pub. date: November 2010.
7: 2 ·J. S ´
anchez et al.
1. INTRODUCTION
It is known that the first sensory-motor activities of a child such as play, move-
ments while playing and observation of the effects of such movements, later
affect the development of the child’s cognitive functions and comprehension
[Piaget 1962]. When a child experiences movements he or she also experiences
notions of time, space and the logic of events, thus learning to make sense of
the entire surrounding environment and achieving an understanding of reality
[Piaget 1962]. For this reason, when children do not develop sensory-motor co-
ordination correctly, they can experience problems in the future with regard to
navigation through their surrounding environment.
In particular, one of the problems for blind people when moving about is
determining their location in the environment and knowing which way they are
facing and the direction in which their body is moving. The lack of information
on important objects in the environment that may serve as anchors and points
of reference for their own position is also important [Hub et al. 2004]. Thus,
any information on the characteristics of the objects in such a context could be
important and relevant for a blind person [Kulyukin et al. 2004].
Our research consisted of providing a technological tool especially designed
and developed for blind people in such a way that they could interact and de-
velop navigation skills. As such, they would be able to know where they are
and make decisions regarding what route to follow in order to get to certain
destinations.
To avoid any potential risks and to move about safely, some blind people pre-
fer to navigate by using the room’s perimeter (shorelining) rather than crossing
through the center of a room. It is simpler for them to continue their route by
touching the wall and thus more easily locating the access points and obtaining
a specific route, than it is for them to move about in open space [S ´
anchez and
Zu ˜
niga 2006]. This way of exploring the environment can lead users to find
inefficient solutions to mobility problems [Kulyukin et al. 2004]. Knowing the
size of a room is not easy, and this is useful information that would help them
to situate themselves. In general, blind individuals can detect the level of echo
produced in a room (either by talking, clapping or tapping their cane) in order
to determine its size.1When a blind individual has more time to walk around
and dedicates time to getting to know and moving about in a closed environ-
ment, he is willing to listen to descriptions and is able to identify details that
allow for a more accurate level of navigation [S´
anchez and Zu ˜
niga 2006].
The majority of meaningful, learning-based, spatial experiences are related
to the use of the body as the central axis of learning, and in this way the
development of psychomotor functions in each individual acquires a funda-
mental role [Berruezo 2000]. The term “psychomotor functions” refers to the
cognitive, emotional, symbolic and sensory-motor interactions inherent in the
ability to be and express oneself in a psychosocial context. Through the prac-
tice of psychomotor functions, a child experiences space, objects, and people.
1Focus Group 2005 Universidad de Chile.
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Improving Navigation Skills for Blind Children ·7: 3
The possibility of discovering and being discovered provides a child with a bet-
ter opportunity to acquire and integrate knowledge of his own body, space and
time into her mental schemes [Berruezo 2000]. Thus, psychomotor functions
allow for the integral development of a child through the interaction of the
body with the external environment; in this way, movement and the person are
related and activated in order to lead the child towards a total form of devel-
opment and balance in all the dimensions involved: motor, affective, cognitive
and social.
Since the womb, the first form of contact with the world around us is through
movement. Learning occurs when a child explores and makes physical contact
with the world around him. This principle was widely studied by Piaget [1954,
1956], who in his studies describes that in the first stages of life, movement is
one of the initial forms of contact with the environment and the surrounding
reality.
Unlike a sighted child, for whom movement emerges from visual curiosity,
a blind child lacks visual experience, such as seeing oneself in the mirror, or
other people, and relating to or feeling a visual attraction to an object. As
this visual possibility for a blind child to be “attracted” to things is absent, her
mobility is diminished, as at first sound is not able to transmit the idea that
there are things that can be touched. With time, however, the development of
a fine-tuned sense of hearing can change this [Nielsen 1989].
In this way, despite the fact that the lack of a visual channel obviously has
repercussions on the ability to obtain information from one’s surroundings, and
on the development of spatial perceptions, it has been shown that a blind or
low-vision child is able to develop the aspects related to spatial orientation just
as well as a sighted child [S ´
anchez 2008]. The difference lies in the use of the
other sensory channels and in the need to know the surrounding environment
in a structured way, thus being able to generate mental schemes that make
it possible to move about in the environment through the implementation of
various strategies that they generate themselves as their spatial abilities in-
crease and their needs and interests continue to determine their need to situate
themselves in space [Arn´
aiz 1994].
2. RELATED WORK
There are several different solutions to help blind users with their orienta-
tion and mobility. One way to help them become more autonomous could be
to provide them with virtual training, so that they are then able to transfer
this learning to the real world. There are several studies in which blind users
use an unknown virtual environment simulator with which they can interact
through both audio [Amandine et al. 2005; Kehoe et al. 2007; S ´
anchez and
Lumbreras 1998; Tzovarus et al. 2002] and tactile cues [Crommentuijn and
Winberg 2006; Crossan and Brewster 2006; Lahav and Mioduser 2008b; Murai
et al. 2006; Pascale et al. 2008].
Having a mental map of space is fundamental for the efficient development
of orientation and mobility techniques. As it is well known, most of the infor-
mation required for such a mental representation is collected through visual
ACM Transactions on Accessible Computing, Vol. 3, No. 2, Article 7, Pub. date: November 2010.
7: 4 ·J. S ´
anchez et al.
channels [Lahav and Mioduser 2008b; Rodrigues 2006; S´
anchez an d Zu ˜
niga
2006]. It is not feasible for blind users to access this information as fast as it
can be done through the use of vision, and they are obligated to use other sen-
sory channels for exploration (audio and haptic as well as other modes) in order
to compensate [Carter and Corona 2008; Lahav and Mioduser 2008b]. Lahav
and Mioduser [2008a, 2008b] have researched the existing relation between
mental representations of space produced by the blind when using virtual en-
vironments with audio and haptic interfaces and their subsequent transfer of
spatial information to the real world. To these ends, they used a virtual en-
vironment modeled on a real one, which the blind user explores in order to
train and improve his real-life navigation skills. The results obtained by these
authors were encouraging, for which reason this study can be used as a base
for researchers regarding the use of virtual environments to develop varying
skills.
One possibility for assisting the blind in their navigation is through the use
of audio-based video games. A variety of studies highlight the importance of the
use of video games for learning [Squire 2003; Steinkuehler 2008]. In particular,
emphasis is placed on the fact that video games have a constructive impact on
the development of problem-solving skills, showing that, after gaming, learners
improve their strategies for understanding, designing, carrying out and evalu-
ating a problem [Klopfer and Yoon 2005; Westin 2004]. Video games can also
allow for the development of specific skills [S´
anchez 2008], promote high-order
learning [Steinkuehler 2008], increase students’ interactions [McDonald and
Hannafin 2003], as well as improve social [Pellegrini et al. 2004] and cultural
[Cipolla-Ficarra 2007] skills. In addition, such games produce a high level of
motivation and commitment for learning which are fundamental aspects that
help to improve the learning activity [Klopfer and Yoon 2005; S´
anchez 2008].
In the work done by Kelly et al. [2007] a shooter-style educational game for
science learning is presented. The authors point to three key aspects in the
design process for this type of game. These are: (a) the design of the game, in
which the strategy and the contents of the game must be clear; (b) the integra-
tion of the video game, which corresponds to the way of presenting the contents
and the interaction between the many elements of the game; and (c) the pro-
vision of multiple levels to construct the simulations and visualizations of the
processes present in the game. The authors emphasize that the success of the
work requires careful coordination between video game designers and those
who review the content, and this is not easy to achieve. On the other hand,
such coordination is essential for the success of an educational video game.
The possibility of using educational video games opens enormous possibil-
ities for working with learners who are blind. It provides the opportunity to
develop more complex skills such as navigation and to do so in a motivating
and challenging way. As digital natives2[Prensky 2001] they find this method
closer to their usual ways of associating with technology [Go and Lee 2007].
For this reason, several authors believe that video games represent a tool that
2A digital native is a person that has grown up with digital technology such as computers, video
games, Internet, mobile phones and MP4s.
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Improving Navigation Skills for Blind Children ·7: 5
allows for a closer approximation to 21st century learners’ ways of learning and
interacting [McMichael 2007; Proserpio and Viola 2007].
S´
anchez and Flores [2008] introduce AudioNature, an audio-based virtual
simulator for science learning implemented through a mobile device platform.
In order to adjust the software to the mental model of users with visual dis-
abilities, a user-centered design methodology is employed. The game presents
an ecosystem that has been altered and challenges learners to return it to nor-
mality through interactive tasks and problem solving. The evaluation of the
software provided evidence that points towards gains in problem solving skills
and showed that mobile learning activities facilitate the user’s interaction with
the software.
Trewin et al. [2008] present PowerUp, a virtual, multiplayer, educational
video game that provides users with a great degree of access. In their paper,
the authors discuss the characteristics necessary for virtual worlds to be us-
able by and accessible to users with some kind of disability. In particular, the
game is accessible to people who are blind due to the configuration of the size of
the letters, text-to-speech feedback, and navigation through the use of the key-
board. The usability evaluation performed shows the interest that blind users
have in immersing themselves in the world of the video games and the virtual
environments, being able to interact without any major difficulties.
Soute and Markopoulos [2007] ventured to develop “Camelot,” a video game
that uses pervasive computing (embedded technology and connectivity as com-
puting devices) in which children construct a castle collaboratively. This kind
of game allows children to interact freely without necessarily realizing that
they are using technology, which produces a high degree of social interaction
spontaneously and transparently.
AudioGene [S´
anchez and Aguayo 2008] is a game that uses mobile technol-
ogy so that blind and sighted children can interact, become socially integrated
and learn science. AudioGene was designed by taking the mental models of
both blind and sighted users into consideration. The goals of AudioGene were
to integrate blind and sighted classmates, teach them science content focus-
ing on genetics, create participative methods for collaboration between blind
and sighted users, and use mobile devices to achieve these goals. The results
showed that there was a real possibility for integrating sighted and blind users
and that the technology, methodology and tools used in this study can help
achieve such a goal.
AudioLink [S´
anchez and El´
ıas 2007] is an audio-based video game that re-
inforces science concepts in a playful environment for legally blind children.
In the game, the players interact with characters and objects in order to com-
plete the game’s central mission. As the child interacts with the game in or-
der to complete the mission, he develops problem-solving skills, learns science
content and develops orientation and mobility (O&M) skills. AudioChile and
AudioVida [S´
anchez 2008] are sound-based games for blind children that are
oriented toward developing problem solving and O&M abilities. In AudioVida,
the halls have a specific mono sound associated with the two intersecting. Thus,
the user is able to know her location when she recognizes an intersection of the
hallways by hearing both specific sounds for each hallway at the same time.
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7: 6 ·J. S ´
anchez et al.
In AudioChile, on the other hand, the user’s location is provided by varying
the intensity of the sound through spatialized sound effects. The evaluation of
the three video games provided evidence that they generate gains in problem
solving skills in children who are blind.
Tim’s Journey [Friberg and G¨
ardenfors 2004] is a video game that allows a
blind user to navigate through virtual spaces that are defined through the use
of specific sounds, thus allowing users to be able to generate a mental repre-
sentation of the space traveled. The results show that users who are blind are
able to navigate through virtual environments when guided by sound. Finger
Dance [Miller et al. 2007] is an audio-based video game that allows a blind user
to develop temporal skills through sound sequences that he must synchronize
with other audible bases in order to achieve the highest possible score. The
results of this work also demonstrate audio perception training for blind users.
It is not enough to merely generate these audio-based video games; rather one
must adopt a new (or ad-hoc) pedagogical methodology based on the lessons or
skills to be taught or practiced [Kickmeier-Rust et al. 2007; Squire 2003].
A user who is blind can enjoy a conventional degree of navigation in a
familiar environment because he knows the surroundings or because he has
adequate aids for navigation. In a closed and unfamiliar environment, the
experience of navigation can be complex and completely nondeterministic
[Kulyukin et al. 2004]. Examples of this are navigating in an airport, hotel,
government building, or a new school, all of which may represent unfamiliar
environments. Having access to some assistance or some training is ideal to be
able to achieve an adequate degree of autonomous and independent movement.
Although there are some forms of assistance, both technological (such as using
GPS or Wi-Fi technology) and nontechnological (such as using guide dogs or a
white cane), for improved orientation and mobility, their benefits are limited in
the context of complex environments. For example, no information is provided
on topological factors or place distribution. Information is only obtained for
the specific location (without references) which does not allow the user to form
a mental map of the entire place. As a result, they cannot guide the user to
choose the best possible route to a certain destination [Rodrigues 2006].
Perhaps a less studied niche is the use of interactive, digital technolo-
gies for the development of skills that are not all stimulated in the con-
text of a classroom or in the school itself; these are orientation and mobility
skills having to do with sensory-motor coordination and tempo-spatial orien-
tation. An adequate degree of control over these abilities is key for school-
aged children in that, without such skills, their communication, interaction,
and movement skills, as well as their autonomy and independence, can be al-
tered. All of these factors are key for appropriate school integration and social
inclusion.
Of all the existing work, we highlight the use of video games for the de-
velopment of skills. Together with this, it is important to consider the use of
different sensory channels, such as audio and touch, by blind users. The focus
of this investigation was to utilize a video game that would provide for a digital
interaction by means of audio and touch in such a way that blind children could
develop orientation and mobility skills.
ACM Transactions on Accessible Computing, Vol. 3, No. 2, Article 7, Pub. date: November 2010.
Improving Navigation Skills for Blind Children ·7: 7
In this article, we present the results of a usability evaluation study that
were previously presented at ASSETS 2009 [S ´
anchez et al. 2009]. This updated
and extended version expands on that initial study and adds new data, results
and analyses of an orientation and mobility evaluation study implemented with
regard to the use of a haptic-based device (Digital Clock Carpet) and a 3D sound
video game (MOVA3D) for the development and use of orientation and mobility
skills in unfamiliar, closed spaces by school-aged, blind children.
3. HARDWARE AND SOFTWARE
Our research was carried out in three main stages. The first stage consisted of
the design and development of the Digital Clock Carpet (DCC) and an audio-
based, 3D video game (MOVA3D). The second stage consisted of the usabil-
ity evaluation of both products with the participation of blind end users. All
users were legally blind, although some had low vision while others were to-
tally Blind. Finally, the third stage consisted of a cognitive evaluation of the use
of the video game (MOVA3D) and the Digital Clock Carpet with blind children.
3.1 Digital Clock Carpet
An hour system for directions was used to tell the user how to get to the des-
tination point. The hour system is a metaphor used for indicating a certain
direction and basically consists of situating the user at the center of an analog
watch. In this system the user is always facing 12 o’clock, so if we want him to
move right we say, “go to 3 o’clock”; to go to the left we say, “go to 9 o’clock”; and
to go backwards we say, “go to 6 o’clock.” This application has the advantage of
having intermediate points that are easy to interpolate; for instance, if we say
the direction is 1 o’clock, the user understands that it corresponds slightly to
the right of his or her current direction. To move forward the user advances one
step in the direction of 12 o’clock. The user controls the speed of his movement
through the force of his body.
For the children to be able to understand and learn the hour system and
in order to provide them with instructions for navigation, a low-cost, haptic
device was designed and built that we called the Digital Clock Carpet (DCC).
According to school curriculum, the children learn the hour system between 10
and 12 years of age. In order to learn and be able to use the DCC, children do
not need to understand or have learned the hour system previously. This device
allows the users to interact directly with their body, performing the movements
naturally. The idea is that users have an alternative and complete input tool
device that goes beyond the mere use of their hands through a keyboard or
some other input device. In fact, the interaction is carried out in the same way
as if he were moving in the real world. Basically, the user performs the turns
that the video game indicates naturally, being able to adjust to the hour system
proposed (1 hour = 1 turn) in the clock location system.
The DCC consists of a wooden base with 12 tactile cells with sensors that
identify the hours of the clock. Each cell corresponds to a large key that the
user can press. These keys close the electric circuit that is sent to the computer
as a logic signal which is interpreted as a conventional keyboard letter. In
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7: 8 ·J. S ´
anchez et al.
Fig. 1. Design of the digital clock carpet.
Fig. 2. Concrete digital clock carpet.
Figure 1 we can see how the carpet communicates with the computer, just like
any other input device such as a keyboard, for which reason it is very simple
and provides the freedom to program the interaction. Each hour is associated
with a letter on the QWERTY keyboard. With this, feedback can be generated
for the user after having captured the events that occur. All communication
is carried out by means of the USB port of any personal laptop or computer
allowing the program to function without any problems; the DCC is thus a
plug-and-play device.
The user interacts with the device by using her body, pressing the different
keys with her feet. In the first version of the DCC, a cylinder that juts out just
1 centimeter above the cell was placed in each cell so that it would be easy for
the users to be able to locate the different keys. In the middle a sandpaper-
like texture was placed, which is a material that the blind are accustomed
to working with (Figure 2). For this texture to be useful for the users, they
interacted with the carpet barefoot (Figure 3). The dimensions of the carpet
included an 80cm radius, and it was 5cm high.
The software for testing the DCC informs the user which direction she
should turn, at which point the child presses the direction (time) that she be-
lieves to be correct with her foot. For each action that the child performs with
the device, there is an associated audio feedback. If the action is correct, a suc-
cess sound is reproduced, and if the user is wrong, an error sound is reproduced.
In addition, when wrong the user is told what time he is really pressing.
After the usability tests, described in detail in Section 4.2, Initial Usability
Evaluation, iterative redesigns were made to the DCC, with which a second and
final version was obtained. This final version incorporated a blue floor covering
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Improving Navigation Skills for Blind Children ·7: 9
Fig. 3. Children interacting with the first (A) and second (B) version of the digital clock carpet
(dcc). (C) The child plays with the video game MOVA3D through interaction with the DCC.
Fig. 4. Evolution of the design and development of DCC (1) The DCC has only the sandpaper in
the middle, (2) First design of the DCC with green haptic feedback, (3) Carpet is added to each key,
(4) The keys are secured with polyurethane tape, and (5) The second and final version of the DCC,
with each key carpeted, sandpaper in the middle, all sealed with polyurethane tape and with the
yellow-colored haptic feedback.
and the haptic feedback was painted yellow, achieving a high degree of contrast
and improving the texture of the carpet for correct use by the users (Figure 4).
The rest of the interaction remained the same. With this new version of the
DCC, a new evaluation was made which is described later in Section 4.3, End-
User Usability.
3.2 MOVA3D
The 3D video game MOVA3D uses 3D graphics and spatial sound which allows
users to navigate freely through the virtual environment. Thanks to spatial
sound, the users achieve a higher degree of immersion in the video game. This
video game was developed following a user-centered methodology, incorporat-
ing children from primary school and aged 6 to 12, from the very beginning of
the design process.
The metaphor that is used in the video game consisted of finding objects in
a virtual environment. To find an object the user has to navigate through the
entire space searching for it, and when he is close, a spatial alarm begins to
sound allowing him to locate the object in space. Once the user picks up the
object, she must bring it to a special area in the virtual environment. On the
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7: 10 ·J. S ´
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Fig. 5. Children interacting with the carpet and the video game. In playing with the carpet, the
child is always facing 12 o’clock, which shifts according to his movements.
way to this special area, the user must make sure that the aliens that inhabit
the surrounding area do not steal the object that she has found. The main idea
is that the children navigate the space in the most complete and precise way
possible. We could simply ask them to do this without any additional problems
to solve, but in this way they perform an additional task beyond what they
already have to do. Thus the excuse that we concocted to stimulate them to
carry out the task is a metaphor. With it they are motivated to complete a fun
task that challenges them and forces them to actively interact with the game
that we designed. In this way, as they are carrying out the mission in the
game, they are obliged to navigate, get to know and recognize the environment
in which the game is immersed, which is also a representation of a real space.
Although the video game was conceived for use through the DCC, it is also
possible to interact by using the keyboard, and thus its use is not only restricted
to when the DCC is available. When the children play the video game through
the use of the DCC, they make movements naturally and guide themselves
through the environment by way of sound and the haptic device (see Figure 5).
When the user interacts with the video game through the keyboard, the
arrow keys are used. Specifically, the up arrow key is for going straight, and
the right or left arrow keys are for turning in the corresponding directions. If
the user pushes the right arrow key, the turn will be clockwise, while if the left
arrow key is used the turn will be counter clockwise.
3.2.1 Audio Interface. The spatial sound is relative to the user’s orientation
and thus accompanies the user throughout her navigation. For this reason, the
audible cues that the user receives while navigating the virtual environment
are always correct and are relative to how the user happens to be situated in
the virtual space. These sounds were provided by a set of speakers placed in
front of the DCC, simulating the spatial sound [Lumbreras and S´
anchez 1999].
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Improving Navigation Skills for Blind Children ·7: 11
The system understands the user’s orientation given that she always moves
by using the clock system, so the turns that the user takes are all controlled
(knowing that she starts off from a certain position). In the video game, it is
impossible for the user to be oriented differently from what the system registers
due to the way in which the player’s interaction is designed.
The user can navigate several floors of a building by using stairs, in which
he/she always obtains audio feedback from the place that is being navigated as
well as from the actions that are performed. The audio feedback that is used
corresponds to the following:
—reproduction of a specific sound when pressing the navigation buttons in the
environment (forward, turn, go up/down stairs);
—reproduction of a specific sound for bumping into an object in the environ-
ment (walls, doors, objects);
—reproduction of a specific spatial sound when the user is close to a stairway
or door;
—reproduction of a specific spatial sound when the user is in the presence of a
watch (an object that must be found within the map);
—reproduction of a specific spatial sound when the user is in the presence of
an enemy when the player has possession of a watch;
—reproduction of information through the use of prerecorded TTS in order to
provide the user with information on his surroundings.
3.2.2 Graphic Interface. The spaces through which the user navigates can
be fictitious representations of an environment or representations of a real en-
vironment. This is thanks to the fact that, in order to generate the virtual
environments, all that is needed are the coordinates of the corners of the walls.
In the video game, real spaces can be represented on their corresponding scale
of representation, as can the objects that are found in the virtual environment.
The video game has textured graphics and characters that make it possible
for students with low vision to take advantage of such visual resources. In ad-
dition, this feature makes the video game attractive for eventual use by sighted
users together with their blind classmates. The main character is a child who
represents the player (Figure 6(a)), and in addition there is a thief (Figure 6(b)),
who tries to take the watch (Figure 6(c)) from the child.
Three environments for navigation were created, each of which represents
an unfamiliar area of buildings in three different Chilean cities where the
research was carried out. In the city of Santiago, the National Electronics
and Telecommunications Center (CENET, for its Spanish acronym) was rep-
resented (Figure 7(a)); in the city of Vi ˜
na del Mar, the Republic of Ecuador
building was represented (Figure 7(b)), and for the city of Concepci´
on, the Help
for the People Who are Blind Corporation (COALIVI, for its Spanish acronym)
building was represented (Figure 7(c)).
3.2.3 Development. The video game was developed using visual studio.net
and c# programming language, to be used with a Windows XP operating system
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Fig. 6. (a) Representation of the child who has a compass hanging from his belt; (b)
Representation of the thief; (c) The object that must be taken from the environment is a watch.
Fig. 7. (a) A room in the CENET building in the city of Santiago. In this room there is a watch
and a thief who is looking for it. (b) A room in the Republic of Ecuador building in the city of Vi ˜na
del Mar. (c) Access hall to the second floor of the COALIVI building in the city of Concepci ´on.
or newer. This application uses the advantages of programming virtual envi-
ronments provided by the Microsoft SDK development tools for XNA. For this
reason, for its execution it is necessary to have Visual Studio Frameworks.NET
3.0 and XNA 2.0.
4. USABILITY EVALUATION
Three usability evaluations were implemented. The first consisted of a Heuris-
tic Evaluation of the Video game (HEV). The second consisted of an Initial
Usability Evaluation (IUE) of the DCC and the MOVA3D video game. Finally,
once iterative redesigns were made to the haptic interface and the video game
according to the results of the IUE, a third evaluation was implemented con-
sisting of an End-User Usability Evaluation (EUE).
4.1 Heuristic Evaluation
4.1.1 Sample. The group of evaluators was made up of 5 experts in us-
ability and interaction, aged between 25 and 35 years old. Four of them were
computer science engineers and one of them was a computer scientist. All of
them had experience and training in human-computer interaction and usabil-
ity evaluation. Three of the experts habitually work with software for blind
people several days out of every week.
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4.1.2 Instruments. The heuristic evaluation was based on systematic in-
spections of the interface. We administered a heuristic evaluation question-
naire (HEQ) based on Shneiderman’s golden rules [Shneiderman and Plaisant
2004] and Nielsen’s usability heuristics [Murai et al. 2006]. This instrument
has been used in other research projects related to interactive systems for users
who are blind [S ´
anchez 2008]. The resulting instrument includes 10 dimen-
sions, covering a total of 25 items in the form of statements about which the
experts are asked to indicate their appreciation on a scale of response with
the following values: strongly agree (5), agree (4), neutral (3), disagree (2) and
strongly disagree (1). The dimensions evaluated were: (I) Visibility of system
status, (II) Match between the system and the real world, (III) User control and
freedom, (IV) Consistency and standards, (V) Error prevention, (VI) Recogni-
tion rather than recall, (VII) Flexibility and efficiency of use, (VIII) Aesthetic
and minimalist design, (IX) Content design and (X) Velocity and media.
For example, the visibility of the system status was evaluated with state-
ments such as, “The software clearly shows where the blind user is” and, “All
possible controls are clearly marked for the blind user.” In the case of Error
prevention, one statement was, “There are messages that prevent possible er-
rors.” Finally, for Content design one statement was, “The content is adequate
to the user’s physical, social and cultural reality.”
4.1.3 Procedure. The heuristic evaluation consisted of the free use of an
advanced and operational prototype of the video game. It began with an in-
troduction to the video game, explaining the objective and the degree of its
development at the time of the evaluation. Then each evaluator proceeded to
interact with the video game, selecting the different options on the menus and
navigating independentlythrough the virtual environment, using the functions
that were available during the evaluation and solving a previously determined
task consistent with finding an object within the virtual environment. To do
this, all they had to do was follow the instructions provided by the software,
and they could take as much time as they needed. After the interaction, each
evaluator proceeded to respond to the evaluation instruments. Finally, a brief
session of analysis and discussion with each evaluator was held in order to col-
lect opinions and comments from the experts on the software, as well as new
ideas and focuses to consider.
4.1.4 Results. With a maximum of five points for each of the heuristics
studied, the results of the HEV came out to an average value of 3.80 points.
This is a significant result considering that the evaluation was made by usabil-
ity experts with a great deal of experience in the development of software for
blind users, and that they were quite critical and rigorous when evaluating the
heuristics (Figure 8). The strengths detected in this evaluation are related to
content design (4.50 points), velocity and media (4.50 points) and recognition
rather than recall (4.50 points). The heuristics with the lowest scores were
visibility of system status (3.00 points) and error prevention (3.00 points). The
main problem was with the use of unrestricted spatial sound, which caused con-
fusion as at times it generated erroneous feedback. After the HEV, the sound
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Fig. 8. Results of the heuristic evaluation of the video game (HRV).
was restricted to the rooms in which an object could be found, in addition to
providing the user with feedback on specific locations in the virtual space.
4.2 Initial Usability Evaluation
4.2.1 Sample. The Initial Usability Evaluation (IUE) was performed with
20 students from the Hellen Keller and Santa Lucia schools for the blind in the
city of Santiago, Chile. Of the 20 users, there were 11 boys and 9 girls; 15 had
low vision and 5 were totally blind; all had different ophthalmologic diagnoses.
The age of the users was between 6 and 12 years old. A usability expert and a
teacher specializing in blind children worked alongside the students.
4.2.2 Instruments. The instrument used for this evaluation consisted of a
scale of appreciation for the user, a scale of appreciation for the evaluators, and
a set of open-ended questions, all regarding the DCC and the MOVA3D video
game. These instruments have already been used in other, similar projects
[S´
anchez and Flores 2008]. The aspects evaluated by the users, through the
use of the scales, were: the voice and sounds are agreeable, clear and easy to
understand and distinguish; the separation and/or central space is big enough
and well delineated; the circular marks are big enough, well marked and delin-
eated; and how much they like this activity. For a higher degree of understand-
ing and to facilitate the evaluation by the children, the scale of appreciation
had a numeric scale from 1 (little) to 10 (a lot).
4.2.3 Procedure. A 20-minute work session per child was established, time
in which they performed movement activities designed for using the carpet
(10 minutes), responded to the scale of appreciation (5 minutes) and answered
the open questions posited by the evaluators (5 minutes).
Initially each child was informed of the activity to be performed. Given that
they had to get to know the DCC, the children were provided with 10 minutes
to explore it however they wanted. During this time, they were asked about the
perceptions or sensations they were feeling, and text area for their comments
and criticisms was provided.
Once the participant felt confident enough with the DCC, she was asked to
take a position in the central part (where the sandpaper is) as a way of provid-
ing the necessary position to initiate the activity. At that same time, without
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Fig. 9. Results of the initial usability evaluation (IUE).
giving them any instructions on the clock system, the participants were asked
to situate themselves facing 12 o’clock. Here it is worth reiterating the fact
that the clock system always changes together with the user’s position, so that
he is always facing 12 o’clock no matter which way he is actually facing on
the clock.
4.2.4 Results.
4.2.4.1 DCC. In general terms, the carpet was perceived as easy to use (9.10
points of a total of 10) (Figure 9). This is supported to a certain degree by the
fact that it is an external device that captures the attention of the participants,
as it differs from the use of other devices that are habitually used to play games
such as the mouse and keyboard on the computer.
As for the size and delineation of the central area of the carpet, this area
was perceived quite favorably (9.30 points of a total of 10). This was identified
immediately thanks to the differentiation in texture; it was even possible to
perceive it through indirect touch with the users’ shoes. The circular marks
that operate as graphic/tactile signals in each of the keys on the carpet were
also positively evaluated by the participants as good references for where each
key is located (9.75 points of a total of 10). The existing distance or separation
between each of the keys caused a less positive perception among the partic-
ipants, as it made their ability to perform well on the activity more difficult
(6.95 points of a total of 10) (Figure 9). The reason for this is that if the keys
are too close together, there could be confusion when locating the desired key.
The delineation of the spaces through the use of graphic/tactile signals was
one of the characteristics of the carpet that the participants liked most (9.30
points of a total of 10) (Figure 9). This is explained by the fact that, thanks to
partial vision or indirect touch (through the shoes) the users were able to not
only know on what part of the carpet they were positioned but to establish a
point of reference when changing directions as well. The graphic/tactile signs
served as a reference for the participants to be able to know where each key
thattheyhadtopushinordertoexecuteanactionwaslocated,whichinsome
cases facilitated the task (8.80 points of a total of 10) (Figure 9).
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In comparing the results according to the degree of the user’s vision (low
vision or blind), it was observed that those with low vision presented slightly
higher averages in the aspects evaluated, which is in line with both the physical
and audio feedback that the haptic device (DCC) provides. However, after ap-
plying the Student’s t-test, these differences were not found to be statically sig-
nificant (Audio Feedback: T(18)=0.296; p>0.05; Haptic Feedback: T(18)=0.440;
p>0.05).
4.2.4.2 MOVA 3D. Regarding the sounds and voices used in the video game,
the level of appreciation by the children obtained scores higher than 5 for all
indicators, with an average of 7.35 points out of a total of 10 (Figure 9). It is
worth highlighting that in this item, no participant pointed out any problems
or changes that should take place as far as the generation of the voice and the
sounds of the video game.
From the very beginning the video game captured the participants’ interest;
each part of the game, in most cases, elicited immediate acceptance and desire
to be part of the experience (9.95 points of a total of 10) (Figure 9). Of the total
number of participants, not one expressed that the video game was boring or
tedious; to the contrary, all the participants found it to be very fun and relaxing
(9.90 points of a total of 10).
4.3 End-User Usability Evaluation
4.3.1 Sample. The End-User Usability Evaluation (EUE) was performed
with 19 students (10 boys and 9 girls) from the Hellen Keller and Santa Lucia
schools for the blind in Santiago, Chile. The ages of the students were between
6 and 12 years old. The users possessed varying ophthalmologic diagnoses, in
that 15 had low vision and 4 were totally blind. The evaluation was focused
solely and exclusively on the modes of interaction and the design of the inter-
faces. These students were different from those who participated in the Initial
Usability Evaluation.
4.3.2 Instruments. For the EUE, the validated Software Usability Ques-
tionnaire for Blind Children was administered. This instrument has been used
in several projects related to sound-based software and blind users [S´
anchez
2008]. The questionnaire consists of 18 sentences for which the users had to
define to what degree each of them was fulfilled, on a scale from a little to a
lot, with quantitative values from 1 (a little) to 10 (a lot). The sentences were:
“I like the software,” “The software is useful,” “The software is challenging,”
“The software makes me active,” “I would use the software again,” “I would rec-
ommend this software to other children/young people,” “I learned through this
software,” “The software has different levels of difficulty,” “I felt I could control
the software’s situations,” “The software is interactive,” “The software is easy to
use,” “The software is motivating,” “The software adapts to my rhythm,” “The
software allowed me to understand new things,” “I like the sounds in the soft-
ware,” “The sounds in the software are clearly identifiable,” and “The sounds in
the software provide me with information.” Note that all sentences are positive,
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Fig. 10. Results obtained in the End-User Usability Evaluation (EUE).
as it is easier for a child to make an evaluation based on a positive statement
than on a negative one. For example, in the case of a negative statement, a
score of 10 (a lot) would imply a poor score, which is the opposite of an eval-
uation with a positive sentence. Such a situation could lead to confusion for
the participating children, and it is for this reason that we rely on positive
statements alone.
4.3.3 Procedure. The EUE was performed with the final version of the
DCC, which was redesigned and improved based on the results obtained from
the Initial Usability Evaluation. (In subsection 3.1, Digital Carpet Clock, we
showed the evolution of the device design).
The application of the MOVA3D video game associated with the DCC de-
vice was also improved, obtaining better audio feedback. In particular, we im-
proved the voice of the assistant and the sound feedback was made more real.
The evaluation was performed during two sessions with two groups of users:
one from the Hellen Keller School and the other from the Santa Lucia School
for the blind in Santiago, Chile. Each student interacted with the device for
ten minutes in order to complete the orientation-based tasks that the virtual
environment proposed.
4.3.4 Results. TheEUEofthesoftwareshowsahighdegreeofevalua-
tion in the 3 dimensions considered, obtaining scores higher than 9.00 points
for all areas (on a scale of 1.00 to 10.00 points, in which 10.00 is the maxi-
mum score). The most highly evaluated scales were Satisfaction and Sounds,
with 9.20 points each. The Control & Use dimension obtained a score of 9.00
points, while the average evaluation for the three dimensions was 9.10 points
(Figure 10).
In analyzing the opinions provided by the users on usability and differenti-
ating by the kind of user involved (low vision or totally blind), no significant dif-
ferences were found. In the Control & Use dimension, the users with low vision
(9.20 points) presented higher scores than the totally blind users (8.50 points).
In the Sounds dimension, the users with low vision (9.50 points) presented
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Fig. 11. Results according to type of vision in the dimensions evaluated in the End-User Usability
Evaluation (EUE). None of the differences were statistically significant.
higher scores than the totally blind users (7.90 points). The differences pre-
sented between both kinds of users were determined to be not statistically sig-
nificant after having applied the Student’s t-test (Control & Use, T(17)=0.724,
p>0.05; Sounds, T(17)=2.439, p>0.05) (Figure 11).
In the Satisfaction dimension, the totally blind users presented 9.40 points,
compared to the 9.10 points presented by those with low vision (Satisfaction,
T(17)=-0.320, p>0.05) (Figure 11).
In the case of the general average, it was observed that low vision users
presented a higher average than the totally blind users, with scores of 9.30 and
8.60, respectively (Mean, T(17)=0.977, p>0.05) (Figure 11).
5. ORIENTATION & MOBILITY EVALUATION
5.1 Sample
For the orientation & mobility impact evaluation, researchers worked with 24
blind children between the ages of 7 and 14 years old. Of these, only 7 were
totally blind and the other 17 had partial vision. All the children had a variety
of ophthalmologic diagnoses and had no other kind of disability. Of the par-
ticipating children, 11 were male and 13 were female. They attend different
schools for the blind from three Chilean cities in particular: Santiago, Vi ˜
na del
Mar and Concepci´
on. In the city of Santiago, we worked with the Santa Lucia
Educational Center and the Hellen Keller School; in Vi ˜
na del Mar, the work
was carried out with the Antonio Vicente Mosquete Institute; and in the city of
Concepci´
on, we worked with the Help for the People Who are Blind Corporation
(COALIVI).
5.2 Instruments
In this study, we measured the learning of O&M skills. An initial measurement
was taken in order to get to know the level of O&M skills that the students
had at the beginning of the intervention (without having used the technology).
Afterwards, a final measurement of O&M skills was taken at the end of the
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Improving Navigation Skills for Blind Children ·7: 19
intervention, measuring the skills that they had gained once they had used
and interacted with the technology (the video game and haptic device).
To these ends, an O&M test was used [Gonz ´
alez et al. 2003] that contains
common and specific indicators that measure different aspects of the degree
of progress that the children have made after having worked on the differ-
ent activities. In total, three dimensions are evaluated: Orientation and Mo-
bility Techniques (36 indicators), Sensory-Motor Coordination (29 indicators)
and Sensory-Spatial Orientation (38 indicators). Some of the indicators used
to identify the achievement of Orientation and Mobility are “Safety and con-
fidence in walking,” “Going up and down stairs,” and “Opening and closing
doors.” For Sensory-Motor Coordination, some examples of the indicators are
“Goes up stairs changing feet without help or support,” “Runs in a straight
line,” and “Marches” (goes to the closest wall, touches it, and comes back). Fi-
nally, for Sensory-Spatial Orientation some indicators correspond to “In front,”
“Behind,” “Diagonal or sideways,” “Recognizes and locates 12 o’clock regard-
ing her position,” and “Recognizes and locates 9 o’clock regarding his position.”
To measure the results, a scale was used with the following values: Achieved
(expresses the expected behavior in its entirety), In process (expresses some
aspects of the expected behavior), and Not achieved (no evidence at all of the
expected behavior). For the purposes of this study, we have included only the
parts of the test that we consider to be pertinent to our research.
This test was organized by age, so that the proposed indicators to be eval-
uated for each of the instrument’s dimensions would be in line with the re-
spective stages of development for the participating children. As such, some
indicators vary or are added based on whether they are applied to children be-
tween 7 and 9 years old, or to children between 10 and 14 years old. For the
navigated areas, the educators used observation guidelines in order to collect
the necessary information on the students’ progress and achievements.
5.3 Procedure
All of the activities with the children were carried out during a period of three
months, in eight sessions that lasted 3 hours and 15 minutes each. For the
preparatory stage, the students worked during one session. The interaction
with the video game was carried out during five sessions, including one session
of real-life navigation in their school, and one session of navigation through
the real space. In one of the sessions the children worked with the concrete
material that represents the real environment on a scale of 1:20. In the
rest of the sessions they played with MOVA3D, using the keyboard and the
DCC device. Two major stages were carried out, Preparation and Navigation
Tasks, in which the children participated by interacting with the MOVA3D
video game.
All of the working sessions scheduled in the respective cities were devel-
oped individually with each of the participants in order to best evaluate each
child. The use of an appropriate physical space that would provide for the com-
fort and relaxation of the participants and evaluators was taken into account.
This protected the emotional state of the participants and thus avoided the
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Fig. 12. Girl participating in the preparatory task.
interference of external variables that could affect the results obtained in the
evaluation.
The tests were administered by an educator who specializes in visual disor-
ders. In order to avoid bias, the pre and posttests were administered by differ-
ent educators. All of the sentences in the test used an objective item format,
for which reason it was simple to evaluate the fulfillment of each item, as the
evaluation consisted of determining whether the user had fulfilled the specific
task or not.
The educators observed the students as they interacted with the technol-
ogy. In the same way, the educators were also present when the students per-
formed the task in the real environmentto then be able to interpret and analyze
the data.
5.3.1 Preparation. The Preparatory stage was centered on the develop-
ment of the hour system through a chronological series of unique movement
sequences with the provision of specific instructions, in which the starting
point was established by positioning the user in the center of the DCC fac-
ing 12 o’clock. For a higher level of understanding of this idea, the position
of the user’s nose was associated with 12 o’clock, which allowed the users to
understand that 12 o’clock on the clock system changes according to the body’s
position in space, which makes it so that the rest of the times are not static,
such as in the use of a conventional watch. Based on this information (the lo-
cation of 12 o’clock), it was possible to guide the users in their search for the
other requested times, relating them to a certain position within the virtual
scene (Figure 12).
5.3.2 Navigation Tasks. These were working sessions in which the chil-
dren interacted with the video game by performing movement tasks regarding
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Fig. 13. Children using the video game and navigating the space in the concrete model, (A) Boy
with the model of the Hellen Keller School, and (B) Boy from the Santa Lucia School for the Blind.
knowledge and recognition of the virtual environment, establishing distances,
location and the delimitation of rooms and halls through the use of sound cues
and graphic information (in the case of users with low vision). At the same
time users performed actions connected to the dynamic nature of these tasks,
which were very useful for strengthening the blind and low-vision users’ famil-
iarization with the video game and the associated external devices. As a result,
the users were able to execute the actions in the video game, using both the
keyboard and the DCC. The following four tasks were performed.
(1) Seeking watches in the virtual surroundings and in the school. The idea
behind this navigational task was for the children to strengthen their
knowledge of the environment, the virtual surroundings and the elements
available within them, in addition to the watches that they had to locate.
With this, it was sought that the participants generate a mental image of
the space from their navigation through the video game.
(2) Work with the video game and with the support of a model made of concrete
material. With this task it was sought to develop learning of the different
areas and elements that make up an unknown environment, in order to
generate a mental image that allows the user to navigate and orient him-
self, and in this way to locate the objects situated in the different rooms of
the virtual environment (Figure 13).
(3) Route within the school. The idea of this task was to get to know the chil-
dren’s abilities for orientation and mobility within a familiar environment,
through the mental images that they already have of that environment.
This task is carried out in their real-life school.
(4) Navigation in the real-world space previously navigated in the virtual
world. Finally, when it was believed that the children had formed a
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Fig. 14. Children navigating through the real space, represented virtually in the MOVA3D
video game.
mental image of the environment, they were taken to navigate the space
that they had been navigating virtually through the video game in real life.
It is through this task that the level of transfer that is achieved by the stu-
dents is determined, as only this will allow them to be able to successfully
find the watch and complete the same objective as in the video game, but in
the real world (Figure 14).
5.4 Results
5.4.1 Navigation Tasks. The 91.60% (22) of the participants successfully
completed Task 1, being able to locate the watches. No task outcomes were
measured for Task 2. In Task 3, 87.50% (21) of the participants successfully
navigated the route within the school, though 3 of the 21 required assistance
in doing so. In Task 4, 83.30% (20) of the participants successfully followed the
real world route that they had practiced in the virtual world.
As the participants navigated the virtual space, they were able to consoli-
date the knowledge that they had of this space. In the beginning, most of the
participants could not remember the exact number of rooms in the video game
or the spatial location of these rooms. Little by little, as they gained more ex-
perience with navigation, they began to pay more attention to the details of
the environment. For example, they were able to recognize if they were on the
first or the second floor and in which specific room they were located. This
was shown in their navigation through the routes that the students took in the
real-life scenario.
In the task of navigation in the real world, all of the students navigated to
find the treasures located in the real-life building based on what they had done
in the virtual scenario which modeled the same rooms. The planning of the
route depended directly on the strategy that each of the participants devised
when positioning themselves in the space and beginning their navigation. In
this way, it was possible for the students to position themselves based on the
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Improving Navigation Skills for Blind Children ·7: 23
references they had learned in the video game and by using the mental image
of the environment that they had constructed during the working sessions.
When faced with the real environment, it was observed that the students dis-
played a certain degree of uncertainty regarding this new scenario. Although it
is safe to assume that they were familiar with the environment virtually, they
had never actually been in this building before.
5.4.2 Pretest/Posttest Comparison. The results obtained are presented for
each group of students separately, given that the tests administered are not
exactly the same for each group, in that they vary according to the age range.
In comparing the means obtained by the 7 to 9 year old users within the
Orientation and Mobility Techniques dimension, it is observed that the mean
score of the pretest (92.00) is lower than that of the posttest (94.11), but with
no statistically significant difference (Student’s t-test(8)= -0.828, p=0.432).
The means obtained by the 7 to 9 year old users in the Sensory-Motor Co-
ordination dimension show that the mean score of the pretest (92.93) is lower
than that of the posttest (97.93), but with no statistically significant difference
(Student’s t-test(8)= -1.145, p=0.285).
In comparing the means obtained for the 7 to 9 year old users in the Tempo-
Spatial Orientation dimension, it is observed that the mean score for the
pretest (68.04) is lower than that of the posttest (83.15). In this case, we
found that this difference is statistically significant (Student’s t-test(8)= -4.973,
p=0.01), which means that there is a higher level of achievement after having
used the software.
In comparing the means obtained by the 10 to 14 year old users in the Orien-
tation and Mobility Techniques dimension, it is observed that the pretest mean
score (78.09) is lower than that of the posttest (80.00), but this difference is not
statistically significant (Student’s t-test(10)= -0,489, p=0.636).
If we compare the means obtained by the 10 to 14 year olds in the Sensory-
Motor Coordination dimension, it is observed that the pretest mean score
(95.55) is lower than that of the posttest (96.5), but with no statistically sig-
nificant difference (Student’s t-test(10)= -0.726, p=0.636).
In comparing the averages obtained for the 10 to 14 year old users in the
Tempo-Spatial Orientation Dimension, it is observed that the pretest mean
score (64.88) is lower than that of the posttest (78.91). This difference is sta-
tistically significant (Student’s t-test(10)=-3,648, p=0.004), which means that
there is a higher level of achievement after having used the software.
6. DISCUSSION
In this article, a usability evaluation is presented for a haptic device espe-
cially designed for this study (Digital Clock Carpet, DCC) and a 3D video game
(MOVA3D), both for the development and use of orientation and mobility skills
in closed, unfamiliar spaces by blind, school-aged children. These evaluations
were used to redesign and improve usability, as well as to inquire unto the de-
gree of acceptance and satisfaction with the end user’s interaction with these
products regarding O&M. In addition, we evaluated the impact that the use of
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the DCC haptic device in combination with the MOVA3D video game and cog-
nitive tasks that represent a real navigational space has on the development
and use of orientation and mobility skills in situations pertaining to closed,
unfamiliar spaces by blind, school-aged children.
The heuristic evaluation helped mainly to redesign and improve the repre-
sentation of the virtual world by means of spatial sound in the software. This
has a relevant impact on the design and development of the MOVA3D video
game if we consider that audio is an input mechanism that provides essential
information for people who are blind. This aspect facilitates and improves the
blind user’s interaction, making it so that he can complete the tasks efficiently.
The initial usability evaluations allowed us to determine the degree of the
users’ acceptance of the haptic interface (DCC) that had been designed, as well
as the quality of the video game’s sounds. The results obtained indicate that
this kind of multimodal interface is a good combination for the development of
orientation and mobility skills in users who are blind.
From the original design of the carpet, it was necessary to include haptic and
visual cues for the children to be able to interact with the DCC device and to be
abletoeasilyidentifytheassociationbetweenthetimeandthekeystrokewith
which they were interacting. For this, material with a highly distinguishable
texture was included in order to generate a high level of haptic sensation. In
addition, the different parts of the device had a high degree of visual contrast
so that those users with low vision could take advantage of their partial vision
as a kind of support during the interaction.
The results obtained from the end-user usability evaluation, after having
used the final versions of the Digital Clock Carpet and MOVA3D video game,
allowed us to infer in more detail unto the degree of the users’ acceptance of
the interfaces and the users’ satisfaction with using this kind of multimodal
interface. This shows how powerful it is to design accessible interfaces that
allow users to enjoy and take advantage of technology in different contexts.
There were no significant differences between the results obtained for users
with low vision and those who are totally blind. Both groups found that that
this kind of interaction was pleasant for them and could be of use for studying
the development of orientation and mobility skills.
So the results show that both the haptic device and the video game are
usable, accepted and pleasant to use for blind children, independently of the
amount of time that they took with the technology and their initial enthusi-
asm. Thus, the video game and haptic device were ready to be used in order to
determine their impact on the development and use of O&M skills.
The fact that the differences between the totally blind users and those who
possess partial vision are not significant is positive for the case of the game’s
usability. This shows that both the MOVA3D video game and the DCC device
work and are useful for both sets of students. Independent of their degree of
visual impairment, the students were able to interact, play, get to know and
navigate the virtual environment without any major difficulties, taking full
advantage of the tools’ capacities.
By taking the usability results obtained in this study into account, we imple-
mented a second step that consisted of evaluating the impact that the use of a
ACM Transactions on Accessible Computing, Vol. 3, No. 2, Article 7, Pub. date: November 2010.
Improving Navigation Skills for Blind Children ·7: 25
tool like the DCC (haptics), in combination with a 3D video game (sound) that
represents a real navigational space, has on the development and use of orien-
tation and mobility skills in situations pertaining to closed, unfamiliar spaces
by blind, school-aged children.
The orientation and mobility results denote that the skills contemplated in
the Tempo Spatial Orientation dimension were strengthened. At the same
time, each of the participants learned that the possibility of moving through
space and establishing a relationship between himself and external objects
makes it possible to know of one’s surroundings.
The only result that was statistically significant for all of the children be-
tween the ages of 7 and 14 was in the Tempo-Spatial Orientation dimension.
This denotes that the users, after having used the video game and the DCC de-
vice, improved their ability to locate themselves in space with a higher degree
of ability regarding laterality, directionality, and spatial concepts. We believe
that this is due to the training that they received when playing with the DCC
device, in which they carried out all of their movements with their own body,
thus internalizing the degree of the turns and better positioning themselves in
the navigated space.
Not having had any significant differences in the other dimensions may be
due to the fact that the users’ initial results were high. Thus the degree of im-
provement could not be that much higher. However, participants were able to
improve substantially in the dimension that obtained the worst pretest results,
the Tempo-Spatial Orientation dimension.
The blind participants were able to create a map of the environment through
sound, which was evident when they took the same route in the real world
that they had navigated virtually through the MOVA3D video game. As the
student played with MOVA3D and interacted through the use of the carpet,
he/she learned the distribution of the rooms, how close together or far apart
they were, and the sizes and distances involved in each room. Some students
counted their steps to then repeat their same movements in the real environ-
ment. Each one of the students adopted a strategy that was useful to them in
being able to learn the topology of the place, to gain a mental representation of
this place, and to then successfully navigate the real space.
However, there was a certain degree of uncertainty among the participants
when they were taken to navigate the real-world routes which did not occur
when playing the video game. Despite the fact that they had navigated the
space virtually, for them there were many aspects of the surroundings that
were still unfamiliar and this caused a certain degree of uncertainty, as ob-
served by the educators. This translated into their using a considerable amount
of time to execute the proposed task, but in any case they were able to orient
themselves in the space, find the different rooms and recover the watch. In
order to minimize the uncertainty, more information on the environment must
be provided during the video game. Although they are able to put together
a mental map, they cannot get to know the textures or differentiate, for ex-
ample, between glass walls and cement walls through the video game. Nor
are they able to know how the banister in the stairway feels from playing the
game. This is a natural process for people when they get to know an unfamiliar
ACM Transactions on Accessible Computing, Vol. 3, No. 2, Article 7, Pub. date: November 2010.
7: 26 ·J. S ´
anchez et al.
environment in which they must relate the different objects in their surround-
ings and learn to interact with them.
7. CONCLUSION
We believe that the learning progress that was made by each child was favored
by positive emotional will, interest in the MOVA3D video game and in the as-
sociated DCC device. This allowed him to strengthen this knowledge, which
went in favor of acquiring new knowledge regarding the use of the video game
and the associated haptic device.
Without a doubt, the new knowledge allowed the users to integrate new
lessons they had learned regarding the environment into the skills involved in
the research. Such skills are not only those associated with the ability to adopt
postures in line with visual needs in order to be able to perform actions on the
carpet (in the case of the participants with low vision) and the ability to situate
themselves in space based on an initial position (in the case of the blind users);
rather the skills include the ability to integrate the clock technique by associat-
ing the position of their body with a particular time, processing this information
and transforming it into a movement that can be made with the haptic device.
This generates movements within the virtual environment and strengthens the
conceptualization and construction of a mental map of the space navigated in
the video game in order for them to be able to then navigate the same route in
the real world.
The MOVA3D video game with DCC and cognitive tasks emerge as an audio-
based tool that can be used for the stimulation of tempo-spatial orientation
skills in blind children. The children who participated in this study were able
to transfer what they learned from the video game to performing the same
tasks in the real world, thus achieving a successful transfer of knowledge and
skills. This transfer is not easy because the children feel uncomfortable at first;
with time, however, the game becomes a significant tool for training.
As a proposal for future research, it would be interesting to add new cog-
nitive skill indicators to those used in the evaluation, thus widening the age
range for the evaluation, in order to be able to include more participants from
middle school education. In the same way, we propose to identify whether the
participants are able to create mental schemes of the environment rather than
maps that merely have some precise elements of the environment, using the
proposed activities. This is a way to research the real effect that the MOVA3D
video game has on the development of orientation and mobility skills through
the use of spatial sound. We really believe that virtual training is better than
real world training, as in the virtual environment it is easier to control all of
the variables and to create different situations in order to improve children’s
skills. In the same way, in the virtual environment the children do not risk
endangerment through their actions.
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