·Abs ac :
Fe nando Díaz del Río Robo ics and Compu e
Technology o Rehabili a ion Lab. Uni e si y o
Se ille (SPAIN) Tel: +34 95 4556144 Fax:+ 34 95
4556449 [email p o ec ed] An ón Ci i Robo ics and
Compu e Technology o Rehabili a ion Lab.
Uni e si y o Se ille (SPAIN) Tel: +34 95 4556470
Fax:+ 34 95 4556449 [email p o ec ed] Juan An onio
P ie o Xime iX ne wo k hough s SL Tel: +34 91
3645475 [email p o ec ed]
Web con en accessibili y o impai ed people has
been mainly add essed by he Web Con en
Accessibili y Guidelines (WCAG) de eloped by he
Web Accessibili y Ini ia i e (WAI) o he W3C
Conso ium. Those guidelines ha e p o ed o be good
diagnos ic means o es ing accessibili y o di e en
ypes o impai men s, as well as o guiding he
de elopmen o accessible con en . A u he s ep
would be o p omo e disco e y o ma e ial ha ing
app op ia e accessibili y suppo , as well as he
adjus men o con ol and display o esou ces o mee
use accessibili y needs and p e e ences [5]. The las
wo challenges ha e been add essed by he IMS
Global Lea ning Conso ium in he IMS-AccessFo All
(ACCMD) and he IMS Lea ne In o ma ion P o ile
(ACCLIP) speci ica ions. Al hough IMS has
app oached bo h goals in a lea ning amewo k, bo h
accessibili y speci ica ions pay a special a en ion o
impai ed use s’ needs. As a i s s ep, in his pape we
su ey how a IMS accessibili y speci ica ions co e
WCAG, and discuss he con enience o ex ending i o
he whole WAI guidelines. Secondly, we a gue how
accessibili y could be conside ed as a key issue o
p omo ing eusabili y. We con inue explaining why
using a seman ic amewo k (such as he MPEG-7
seman ic ool, RDF o OWL) o desc ibing ex ual
and con ex ual in o ma ion in a s anda dized manne
could p omo e bo h, accessibili y and eusabili y.
Finally, we explain how some accessibili y issues
ha e been al eady add essed by Xime iX’s ximDEX,
a seman ic-web Con en Managemen Sys em (CMS).
We conclude p oposing a plan o be e in eg a e he
accessibili y speci ica ions and con ex ual desc ip ion
ools in o ha CMS.
Keywo ds:
Me ada a, Accessibili y, Reusabili y, CMS, Dublin
Co e, IEEE-LOM, IMS-AccessFo All, ACCMD,
IMS-Lea ne -In o ma ion-P o ile, ACCLIP, Seman ic
Web, MPEG-7, RDF, OWL.
1 In oduc ion
In he ACCMD and ACCLIP speci ica ions, he
e m disabili y has been e-de ined as a misma ch
be ween he needs o he lea ne and he educa ion
o e ed, i.e. he abili y o he lea ning en i onmen o
adjus o he needs o all lea ne s [5]. Ne e heless, he
needs and p e e ences o a use may a ise om he
con ex o en i onmen he use is in, he ools
P omo ing accessibili y by using me ada a in he
amewo k o a seman ic-web d i en CMS
Rocío Ga cía-Robles
Robo ics and Compu e
Technology o
Rehabili a ion Lab.
Uni e si y o Se ille
(SPAIN)
Tel: +34 95 4556144
Fax:+ 34 95 4556449
[email p o ec ed]
Fe nando Díaz del Río
Robo ics and Compu e
Technology o
Rehabili a ion Lab.
Uni e si y o Se ille
(SPAIN)
Tel: +34 95 4556144
Fax:+ 34 95 4556449
[email p o ec ed]
An ón Ci i
Robo ics and Compu e
Technology o
Rehabili a ion Lab.
Uni e si y o Se ille
(SPAIN)
Tel: +34 95 4556470
Fax:+ 34 95 4556449
[email p o ec ed]
Juan An onio P ie o
Xime iX ne wo k hough s SL
Tel: +34 91 3645475
[email p o ec ed]
DC-2005: P oc. In . Con . on Dublin Co e and Me ada a Applica ions 2005 ~71
·This wo k has been pa ially suppo ed by he SIC (Se icio de
In o má ica y Comunicaciones) o he Uni e si y o Se ille.
a ailable (e.g., mobile de ices, assis i e echnologies
such as B aille de ices, oice ecogni ion sys ems, o
al e na i e keyboa ds, e c.), hei backg ound, o a
disabili y in he adi ional sense [5]. Accessible
sys ems adjus he use in e ace o he lea ning
en i onmen , loca e needed esou ces and adjus he
p ope ies o he esou ces o ma ch he needs and
p e e ences o he use . The e o e, accessibili y no ion
has been enla ged in he IMS scope, o add essing no
only impai ed people needs, bu also o he use s’
(lea ne s’) p e e ences. On he o he hand, he e a e
wo sides o he ma ch needed o add ess he use s’
needs and p e e ences. One speci ies wha he use
needs o p e e s, and i is cu en ly desc ibed by he
ACCLIP. [5] The o he labels esou ces using he
same e ms, and i is cu en ly desc ibed by he
ACCMD. Resou ce accessibili y desc ip ion is also
being add essed by he DC-Accessibili y Elemen and
IEEE-LOM, as i is u he explained in nex sub-
sec ions.
1.1. The IMS AccessFo All In o ma ion Model
The inal goal o his IMS speci ica ion is o
p o ide unc ional in e ope abili y o suppo he
subs i u ion o augmen a ion o one esou ce wi h
ano he when his is equi ed o accessibili y
pu poses, as p esc ibed in he use ’s p o ile (e.g., he
addi ion o cap ion ex o a hea ing-impai ed
con ex ), hus allowing in e ope a ing sys ems o wo k
oge he o se e he needs o lea ne s wi h disabili ies
and o he s who ha e ACCMD p o iles. The IMS
o e all accessibili y da a model [6] consis s o he
desc ip ion o one p ima y esou ce, and he
desc ip ion o he ea u es o none, one o mo e
esou ce(s) ha a e equi alen s o a pa icula
p ima y esou ce. A p ima y esou ce is allowed o
poin o ze o o mo e equi alen esou ces. An
equi alen esou ce is allowed o poin o a single
p ima y esou ce only. In his way, ci cula e e ences
a e a oided and he ela ionship model is g ea ly
simpli ied wi h no loss o unc ionali y. The p ima y
esou ce me ada a desc ibes: -Access Modali y: I
includes ou a ibu es such as hasVisual,
hasAudi o y, hasTex , and hasTac ile, which a e
boolean alues o indica e whe he o no he esou ce
con ains isual, audi o y, ex ual o ac ile equi alen
con en in o ma ion. -Adap abili y: How amenable he
esou ce is o ans o m he display and whe he he
me hod o con ol is lexible (display ans o mabili y
and con ol lexibili y). -Equi alen : Whe he he e is
a known equi alen al e na i e. I is a poin e o an
equi alen esou ce (me a-da a) o he desc ibed
esou ce o pa s he eo . The equi alen esou ce da a
model con ains h ee elemen s ha a e con aine s o
con en p esen ed in a di e en modali y:
al e na i esToVisual (colou a oidance such as ed,
o ange, ed/g een,…… o he use o maximum
con as monoch ome); al e na i esToTex (e.g.
g aphic al e na i e o sign language al e na i es o ex
in he p ima y esou ce); al e na i esToAudi o y
(cap ions, educed eading le el, educed speed, o he
a ailabili y o sign languages al e na i es). The o he
elemen a ibu es a e he lea ne Sca old, and he
con en , bo h o hem di ec ly ela ed o he lea ning
app oach o he IMS speci ica ions. Ne e heless, he
o he h ee elemen s desc ibe he accessibili y
equi emen s ela ed o impai men s, and he e o e a e
ela ed o he WCAG de eloped by he W3C. To apply
an accessibili y app oach acco ding o ACCMD, he
no mal wo k low would be: A-Ask use , (a leas i s
ime using a new applica ion), o his/he p e e ences.
The mos likely way is h ough an in e ac i e o m
(‘wiza d’) ha p esen s a numbe o ques ions o he
use and, gi en esponses o he ques ions, gene a es
he p o ile. The p o ile should be ac ed on each ime
he use uses ha applica ion, and he implemen e s
should ensu e ha hei in e ace makes i easy o ac
hem o , o o modi y he p o iles by he use . B-
When a use sea ches o con en , he use ’s p o ile
should be aken in o accoun when displaying he
sea ch esul s. The e o e, once esou ces ma ching he
sea ch c i e ia a e ound, he me ada a o hese
esou ces should be examined o de e mine i he
esou ce ma ches he p e e ences in he use ’s p o ile.
The esou ces should be anked acco ding o how well
hey ma ch each p e e ence and any pa ial ma ches
should be lagged as such. The usage elemen s in he
use ’s p o ile should be used o ank he esou ces.
Use s should be gi en he op ion o eques ing ha
pa ial o non-ma ches be omi ed om he sea ch
esul s. C-I he eques ed esou ce has no ACCMD,
he sys em should wa n he use . I he eques ed
esou ce has ACCMD, he sys em should ma ch he
use p e e ences. This p ocess would be no mally
au oma ed, bu bes p ac ice ecommends ha use
con ol o e he au oma ion beha iou be an
implemen a ion ea u e o he sys em
1.2. The DC Accessibili y Elemen
The DC-Accessibili y Wo king g oup (DCA-WG)
is p oducing a se o documen s ha could lead o he
c ea ion o a new DC elemen o be called
DC:Accessibili y. The desc ip ion o he e m should
be simpli ied and some possible ex alues o he
e m should be speci ied [9]. The unde lying
in o ma ion model o he new e m could be closely
ela ed o he ACCMD ha desc ibes people’s
accessibili y needs and p e e ences. Bo h
speci ica ions, o people and o esou ces, we e
de eloped in collabo a ion wi h he IMS Global
72 DC-2005, Sep embe 12-15 - Mad id, Spain
P ojec and hey a e main ained by ha body. To
comple e he wo k, DC needs an applica ion p o ile o
elemen se ha desc ibes people in which hei
accessibili y needs can be included. The e o e, his
app oach o accessibili y, as he one adop ed by he
IMS, depends upon no jus accessible con en 1
(WCAG con o man ), bu also ha esponsibili y o
accessible con en deli e y be aken by he se e .
This is a shi om ea lie app oaches which depended
solely on WCAG/ATAG/UAAG con o mance. I is
consis en wi h o he wo ks ha aims o p o ide mo e
de ice lexibili y o use s. Fu he in o ma ion on he
DC:Accessibili y elemen could be published in he
DCMI websi e2.
1.3. The IEEE LOM and CEN-ISSS
The Eu opean S anda diza ion body, CEN-ISSS has
s a ed a Lea ning Technology Wo kshop on
Accessibili y P ope ies o Lea ning Resou ces
(CEN-ISSS LTW APLR). The main objec i es o ha
wo kshop a e [10]: -To demons a e o ma i e ways
ha he IEEE LOM can be used o documen
in o ma ion abou he accessibili y p ope ies o
lea ning con en (lea ning objec s) in s anda d ways. -
To de elop a basic ocabula y and amewo k a ound
which so wa e endo s, ool p oduce s and con en
au ho s can wo k in o de o p o ide a g ea e le el o
in e ope abili y and applicabili y o ools. The esul s
o ha on-going p ojec will be [10] -Accessibili y
applica ion p o ile o he IEEE LOM o desc ibe
accessibili y equi emen s (CWA); -Recommenda ions
o u he wo k in he ligh o global accessibili y
a chi ec u e and me a-da a de elopmen s and
po en ials o use - ials. Pa o hose esul s will be
[10]: -Me ada a Vocabula ies, con aining accessibili y
ocabula ies o desc ip ion o accessibili y
cha ac e is ics o lea ning esou ces. -IEEE LOM
Applica ion P o ile and Binding, con aining he
in o ma ion model o he Accessibili y applica ion
p o ile o he IEEE LOM and he co esponding RDF
Binding. -Accessibili y Con o mance Tes ing Plan, a
con o mance es ing plan wi h he Accessibili y
applica ion p o ile o he IEEE LOM. The ac i i y o
he CEN-ISSS LTW APLR is being coo dina ed and
ha monized wi h o he in e na ional s anda ds
o ganiza ions such as IMS, ISO, DC and W3C/WAI
[8]. The e is no single uni e sally accep ed axonomy
o unc ional me ada a ha sui s he pu pose o
con en adap a ion o he indi idual o accessibili y. I
is he ecommenda ion o his g oup ha such a
axonomy be de eloped and kep in a public me a-da a
egis y o e ing mul ilingual and cul u al-con ex
anspa ency and be e e enced o con en - ela ed
alues [10]. A s ep owa ds his wo k is p o ided by
he ex ensions o LOM, which include [10]: -Requi ed
new ocabula y alues o
Rela ion:Kind displayT ans o mabili y
con olFlexibili y equi alen Resou ce al e na i eFo
supplemen a yFo
-New elemen wi hin Rela ion:Iden i ie
Pa
Ca alog
En y
The e o e, a e his b ie in oduc ion o he wo k
unde de elopmen by he CEN-ISSS LTW APLR, we
can conclude ha i is also a lea ning o ien ed
accessibili y speci ica ion, whose main goal has been
basically o adap he IMS ACCMD speci ica ion o
he IEEE-LOM s anda d. The unde lying accessibili y
in o ma ion model is exac ly he same, bu using
di e en label names. Some issues s ill need
e inemen because he wo k is s ill in p og ess.
2. The IMS accessibili y speci ica ions and
he WCAG
Web Con en Accessibili y Guidelines (WCAG) a e
cu en ly a de ac o s anda d o check Web con en
accessibili y o impai ed people. WCAG con ains an
exhaus i e lis o checkpoin s o guidelines ha a page
should ul ill i i is o be conside ed as accessible by
e e ybody. The i s e sion [1] o ha lis (WCAG
1.0, 1999) was somewha echnology o applica ion
dependen : many checkpoin s we e add essed o an
h ml implemen a ion o pages. This ac was censu ed
many imes by web communi y. Ne e heless he
eedback and dissa is ac ion a ound e sion 1.0 has
d i en WAI Wo king G oup o p oduce a mo e
“ obus ” ( echnology independen ) WCAG 2.0
guidelines. Those a e cu en ly in p og ess, bu d a
e sion [2] is clea enough o unde s and his end.
Ano he p oblem s ill emains: au oma ic checking o
accessibili y o a page is a challenge. Some ools ha e
been de eloped o add ess ha issue, bu a web
p og amme can mislead hose ools. Fo example, i a
page includes an emp y ag as “al e na i e” desc ip ion
o a non- ex ual elemen , mos o checking ools will
assume ha al e na i e desc ip ion is co ec ly
co e ed. In ac , ac ually, a CMS mus gua an ee ha
all he p ope ies o e i y accessibili y o a desi ed
le el a e p o ided ei he di ec ly om he con en
c ea o (policy-1) o indi ec ly using ules o ex ac
hem om he con ex o om p e ious elemen s o
DC-2005: P oc. In . Con . on Dublin Co e and Me ada a Applica ions 2005 73
1Being c ea ed wi h good au ho ing ools o use wi h good use
agen s (ATAG and UAAG complian ).
2Ne e heless, i is impo an o ema k ha due o he ac ha
he e is a p oposal pending in he DCMI in ela ion o a possible
accessibili y elemen , i can no assume ha he o icial publica ion
is a p o o ma s ep.
in o ma ion in he hie a chy (policy-2). The CMS
p esen ed in his pape , ximDEX, has implemen ed
bo h policies. On he o he hand, a u he s ep
ollowing WAI G oup ini ia i e would be o p omo e
disco e y o ma e ial ha ing app op ia e accessibili y
suppo , as well as he adjus men o con ol and
display o esou ces o mee use accessibili y needs
and p e e ences [8], (as explained in sec ion 1.1 o he
cu en documen ). This is pa ially add essed by he
IMS ACCMD and ACCLIP speci ica ions. The
unde lying In o ma ion Models o bo h o hem a e
no exhaus i e, bu he add essed accessibili y issues
a e sui ably s uc u ed in a hie a chically manne . So,
al hough he concep o accessibili y is mainly aimed
o he ield o elec onic lea ning in IMS
speci ica ions, we conside i is jus a p omising
s a ing poin . We sugges ha i is a key issue o
ex end he IMS In o ma ion Models o including all
WAI guidelines. Ne e heless, ha is no a i ial
wo k, no an easy ask. Fi s o all, IMS de ines a
model (ACCLIP) which desc ibes and eco ds use
p e e ences, i.e. he use p o ile. This model is he
base o la e adap page elemen s o he use . Then,
his model should be augmen ed o ake in o
conside a ion all he abili ies o e e y po en ial Web
use (so ha i co e s all ea u es encoun e ed in
WCAG guidelines). So e e y use and Web de ice
(use agen in WAI e minology) will ha e o alue he
pa ame e s o he use p o ile be o e displaying
con en . Mo eo e , hose pa ame e s may be uned
along he new accesses o eco d mo e exac ly he
cha ac e is ics o he use . F om he con en display
poin o iew, i will be necessa y o de ine he
accessibili y p ope ies o each elemen o a page.
Wi h espec o accessibili y, Web elemen s can be
classi ied in o some ew g oups: ex ual, links, audio,
ideo, pic u es, ables, cha s and ew mo e. Each one
has di e en p ope ies ha will de ine i s accessibili y
ea u es. Fo example, audio con en has wo
impo an p ope ies: con aining ele an in o ma ion,
o playing he ole o en e ainmen elemen s. On he
second le el o he hie a chical p ope ies, he audio
elemen s ha con ain ele an in o ma ion will ha e
an impo an p ope y: being ex ual (e.g. ly ics o a
song, cap ion o an audio con e ence,……). Then, an
elemen wi h his las p ope y will inhe i he no mal
ex ual p ope ies. Conside ing he p ope ies o all
elemen s o a page, he use disabili ies and
p e e ences and de ice ea u es, he b owse would
display he page in o ma ion in he mos app op ia e
manne . Ob iously, he e is oo much wo k o do in
ela ion wi h he p e ious p oposal. The con e sion o
WCAG 1.0 checkpoin s in o WCAG 2.0 guidelines
has inc eased accessibili y abs ac ion, which can help
as a i s s ep o model con en accessibili y p ope ies
in a echnology independen way. Bu i is necessa y
o go on.
2.1 O e iew on cu en ends in ela ion o he
de elopmen o a comple e accessibili y
speci ica ion
IMS has al eady de eloped he accessibili y
speci ica ions hey needed o lea ning and lea ne s
pu poses. Bu IMS does no in end o do he ACCLIP
and ACCMD comple ely o esemble he WCAG, as i
can be in e ed by he ollowing s a emen : “Me a-da a
o asse compliance o an accessibili y speci ica ion
o s anda d is no wi hin he scope o his
speci ica ion.” [5] Simul aneously, he DC Me ada a
Ini ia i e (DCMI) is cu en ly wo king on he DC
Accessibili y Elemen . DCMI usually ends o ge he
minimum se o agging elemen s, while IMS usually
de elops e y de ailed and huge speci ica ions, whose
in o ma ion models a e usually e y hie a chical.
Conce ning he wo k unde de elopmen by he
CEN/ISSS in ela ion o he IEEE LOM speci ica ion,
ha is also a ho izon al speci ica ion and axonomy
o ien ed, as he DC Me ada a Se . IEEE LOM and
IMS speci ica ions a e e y lea ning o ien ed, while
DC is much mo e gene ic. Taking in o accoun all
hese ac o s, i is mo e likely ha he DCMI and he
CEN/ISSS a e in e es ed in enla ging i s speci ica ion
o complying wi h he ACCMD han comple ing he
ACCMD o co e ing he whole WCAG and o he
WAI guidelines. Ne e heless, i would e y
con enien o con inue enla ging and e ining he IMS
accessibili y speci ica ions o co e all he WCAG,
because IMS, DC and IEEE ha e ini ia ed he
s anda diza ion p ocess which logically ollows he
p e ious wo k unde aken by he W3C, bu no all he
accessibili y guidelines a e add essed ye .
2.2 WCAG 1.0 s. WCAG 2.0
Al hough WCAG 2.0 a e nowadays only a wo king
d a , i is impo an o ake in o accoun he main
di e ences ela ed o e sion 1.0, be o e compa ing
WCAG wi h he ACCMD. Some o he main
di e ences be ween bo h a e he ollowing ones [8]:
1-WCAG 2.0 ep esen s b oad concep s ha apply o
all Web-based con en . They a e no speci ic o
HTML, XML, o any o he echnology s. e sion 1.0
which was highly echnology dependen . 2-Whe e
WCAG 1.0 uses guidelines o g oup checkpoin s,
WCAG 2.0 uses guidelines o g oup success c i e ia.
Whe e WCAG 1.0 assigns a p io i y o a checkpoin ,
WCAG 2.0 ca ego izes a success c i e ion in o one o
h ee le els. The e o e, newes e sion is mo e
e icien ly o ganized. 3-WCAG 2.0 may adjus he
p io i y o some checkpoin s. We conclude ha
because WCAG 2.0 is mo e abs ac , i is easie o
74 DC-2005, Sep embe 12-15 - Mad id, Spain
compa e i wi h he ACCMD, as we will see in nex
sec ion.
2.3 IMS AccessFo All s. WCAG 2.0
Compa ing WCAG 2.0 Design Guidelines ( op
laye ) wi h he ACCMD in o ma ion model, we can
obse e ha WCAG p inciples 1, 2 and 4 a e pa ially
co e ed: -P inciple 1: Con en mus be pe cei able.
This means (1.1) he e mus be ex al e na i es o all
non- ex con en ; (1.2) p o iding synch onized
al e na i es o mul imedia (cap ions and audio
desc ip ions); (1.3) ensu ing ha unc ionali y and
s uc u e a e sepa able om p esen a ion. -P inciple
2: In e ace elemen s in he con en mus be ope able.
This means (2.1) Making all unc ionali y ope able ia
a keyboa d in e ace;
(2.2) allowing use s o con ol ime limi s on hei
eading o in e ac ion; (2.3) allowing use s o a oid
con en ha could cause pho osensi i e epilep ic
seizu es; (2.4) p o iding mechanisms o help use s
ind con en , o ien hemsel es wi hin i , and na iga e
h ough i . -P inciple 4: Con en mus be obus
enough o wo k wi h cu en and u u e echnologies.
This means (4.1) using echnologies acco ding o
speci ica ion; (4.2) ensu ing ha use in e aces a e
accessible o p o ide an accessible al e na i e(s).
Mos o he abo e men ioned design p inciples a e
only pa ially suppo ed by he ACCMD. Fo example,
some o he unco e ed design p inciples a e lis ed
below: -P inciple 1.4: Making i easy o dis inguish
o eg ound in o ma ion om backg ound images o
sounds. -P inciple 2.5: Helping use s a oid mis akes
and make i easy o co ec hem. -P inciple 3:
Con en and con ols mus be unde s andable. Tha
means (3.1) ensu ing ha he meaning o con en can
be de e mined; (3.2) o ganizing con en consis en ly
om “page o page” and making in e ac i e
componen s 5 beha e in p edic able ways. The
a o emen ioned design p inciple 3 may be managed by
using o he IMS speci ica ions such as IMS Simple
Sequencing o IMS Lea ning Design, bu bo h o hem
a e lea ning o ien ed. In ou opinion, one o he nex
s eps would be inding he in o ma ion model ha
ela es as much as possible he WCAG guidelines, by
enla ging he cu en speci ica ion, and making i less
dependen on he lea ning app oach. The e is also a
need o de eloping ools o display con en in an
accessible way. Fo example, he abo e men ioned
p inciple 1.4 could be managed by using he sui able
ools. Bu a he same ime, i would be in e es ing o
ha e a me ada a elemen o desc ibing o a conc e e
con en esou ce i he o eg ound in o ma ion is
easily dis inguishable om backg ound image o
sound, ( ha label could be illed up by a pe son, o
au oma ically by a diagnos ic ool).
2.4 Tex ual In o ma ion is he linking o ma
be ween accessible and no accessible con en
Acco ding o he i s design p inciple o he
WCAG 2.0 “con en mus be pe cei able”. This means
(1.1) he e mus be ex al e na i es o all non- ex
con en ; (1.2) p o iding synch onized al e na i es o
mul imedia (cap ions and audio desc ip ions); (1.3)
ensu ing ha unc ionali y and s uc u e a e sepa able
om p esen a ion. I we analyze he implica ions o
ha design p inciple, we can in e ha ex ual o ma
ac s as a middlewa e o accessibili y pu poses. On
one hand, isual in o ma ion needs ex ual desc ip ion
in o de o be ansla ed o o he o ma s (e.g. audi i e,
sign language). On he o he hand, in o ma ion in
audio o ma also needs o be cap ioned as a p e ious
s ep o i s ansla ion o o he accessible o ma s, o
example o a hea ing-impai ed con ex . Some imes
non- ex o ma can be cap ioned, bu some imes i
mus be jus desc ibed, i.e. i mus be con ex ualized.
The e o e, as we will explain in nex sec ion, he e
should be p ope suppo o desc ibing ex ual and
con ex ual in o ma ion.
3. A u he s ep: S anda diza ion on he
desc ip ion o ex ual and con ex ual in o ma ion
As explained in he p e ious sec ion, ex ual
in o ma ion is he linking o ma be ween non-
accessible and accessible con en . In ou opinion,
accessibili y can be conside ed one key issue o
p omo ing eusabili y (unde s ood as he capaci y o
con en o be eused in in a and in e con ex ual
scena ios). On one hand, he wide he po en ial use
communi y is, including disabled people, he wide he
chances o eusing con en . On he o he hand, as
explained in p e ious sec ion, in o de o suppo
accessibili y i is use ul o o ganize he in o ma ion in
a ex ual o ma and, as a consequence, once he
in o ma ion is in ha o ma i is easie o euse i
u he on. The e o e, accessibili y me a-in o ma ion
con ibu es o enla ging he eusabili y capaci y o
con en . So, o make con en mo e accessible is also o
make i mo e eusable. I is a powe ul ad an age i
we ake in o accoun ha he human esou ces
cu en ly needed o de eloping con en binding IMS,
DC, IEEE and o he speci ica ions is eno mous. Due
o ha eason, eusabili y could e en be conside ed a
eal goal, be e han jus a desi able. I we hink in
e ms o eusabili y, acco ding o [13], he e a e h ee
key ac o s p omo ing i : (a) g anula i y ( he lowes
he be e o eusabili y pu poses); (b) localiza ion
(me ada a is mainly suppo ing ha aim); and (c) sel -
con ained-ness, (unde s ood as he capaci y o con en
o be con ex independen ). Conce ning he las ac o ,
DC-2005: P oc. In . Con . on Dublin Co e and Me ada a Applica ions 2005 75

de eloping neu al con en is agains he usual con en
au ho ing wo k low, because human beings no mally
con ex ualize when au ho ing con en . So, de-
con ex ualiza ion and e-con ex ualiza ion a e
eques ed s ages no mally when ying o euse
con en . The e o e, we can conclude ha desc ibing
con ex (no mally exp essed as ex ual in o ma ion),
could p omo e con en eusabili y, as well as
accessibili y. I could ac as a acili a o o inding
con ex ual issues in a speci ic con en , in a p e ious
s ep o he de-con ex ualiza ion and e-
con ex ualiza ion o con en . Consequen ly, i could be
in e es ing o desc ibe ex ual and con ex ual
in o ma ion using a speci ica ion 3 , e.g. a seman ic
amewo k. In o de o suppo con ex desc ip ion,
se e al app oaches a e possible. I we wan o desc ibe
small pieces o in o ma ion, e.g. ques ion i ems, a
domain on ology suppo ed by OWL o RDF could be
a solu ion. On he o he hand, i we wan o desc ibe
highe g anula i y pieces o in o ma ion (bo h da a and
p ocesses), o he ypes o na a i e o ien ed solu ions
could be be e used. Indeed, he e a e some s anda d
speci ica ions o he desc ip ion o con ex . In IMS
lea ning o ien ed speci ica ions, as well as he DC
Elemen Se and he IEEE LOM, con ex is cu en ly
mainly desc ibed in e ms o domain ocabula ies
used in he me ada a ags. The Desc ip ion and Tex
elemen s o he DC Me ada a Se , IMS-Me ada a and
he IEEE-LOM can also be used o ex ual
desc ip ion. RDF and OWL a e also e y powe ul
ools o desc ibing con ex in an on ological o ien ed
manne . Ano he speci ica ion which may suppo he
desc ip ion o con ex is he IMS-Lea ning Design
(IMS-LD) [11]. I does i using an unde lying na a i e
syn ax (exp essed in e ms o oles playing ac i i ies
using esou ces). The main disad an age o using his
speci ica ion o con ex desc ip ion is ha i is
o ien ed o he pedagogical desc ip ion o lea ning
expe iences. So, i can be e y good, o example o
desc ibing a uni o lea ning o lea ning scena io, bu
i could be no sui able o gene al pu poses. Ano he
speci ica ion o con ex desc ip ion is he MPEG-7,
[14] being much mo e gene ic han he IMS-LD. I
suppo s he desc ip ion o bo h: he s uc u e ( ideo
segmen s, mo ing egions, e c) and he seman ic. The
MPEG-7 seman ic en i y ools desc ibe seman ic
en i ies (such as na a i e wo lds, objec s, e en s,
concep s, s a es, places and imes), as well as seman ic
ela ionships be ween hem. In MPEG-7 e en s a e
unde s ood as occasions when some hing happens.
Objec s, people and places can popula e such
occasions and he imes a which hey occu .
Fu he mo e, hese en i ies can ha e p ope ies and
s a es h ough which hey pass as wha is being
desc ibed anspi es. Finally, he e is he wo ld in
which
all o his is going on, he backg ound, he o he
e en s and o he en i ies, which p o ide con ex o
he desc ip ion. [14] The main ad an age o using
MPEG-7 would be o gi e seman ic s uc u e o he
desc ip ion. Tha seman ic s uc u e could be e y
use ul o suppo ing design p inciples 3 and 2.5 o he
WCAG 2.0. Ano he addi ional ad an age o using
MPEG-7 speci ica ion is ha i is a gene ic
speci ica ion de eloped o desc ibing mul imedia
con en and, as explained in p e ious sec ions, we a e
discussing he con enience o desc ibing non- ex ual
in o ma ion o accessibili y as well as o eusabili y
pu poses. The e o e, we can conclude ha he main
ad an age o he a o emen ioned explained solu ions
(OWL/RDF, DC Elemen Se , IEEE-LOM, IMS-
Me ada a4), is ha hey a e na u al language o ien ed,
and p obably hey a e less cos ly in e ms o human
and machine esou ces. IMS-LD and MPEG-7 a e
mo e complex and na a i e o ien ed solu ions, bu
maybe oo cos ly in p ac ice i hey a e used o
desc ibing con ex .
4. XimDex: A Seman ic CMS
The seman ic Con en Managemen Sys em
ximDEX [3] is a isual amewo k de eloped by
Xime iX o he c ea ion o web con en s unde he
pa adigm o he Seman ic Web. The main ocus o he
pla o m is he abs ac ion o con en s and se ices,
o e ing a dis ibu ed and isual en i onmen o he
anno a ion and pa ame e isa ion o elemen s o
in o ma ion ha a e agg ega ed in o a hie a chy o
documen s in a classic web po al app oach and in o
nodes and ela ionships con o ming seman ic
eposi o ies o in o ma ion o he managemen o
Seman ic po als. Elemen s o in o ma ion
ep esen ing con en s and se ices a e g ouped in o
documen s ep esen ed ia a neu al seman ic o ma
[4]. Du ing he anscoding (con e ing om one
o ma o ano he ) s age [15, 16], a p o iling o hese
elemen s o in o ma ion is made o c ea e inal
exploi able o ma s.
4.1 Accessibili y buil in ximDEX
E e y elemen o in o ma ion composing a
documen o se ice has me ada a p o ided by he
c ea o s and/o calcula ed om in e ences using he
ins an aneous con ex o he elemen o in o ma ion
(ances o ’s p ope ies o ins ance) in o de o p o ide
addi ional unc ionali ies and o gua an ee he
accomplishmen o a ge s (whe e accessibili y is
76 DC-2005, Sep embe 12-15 - Mad id, Spain
3A p o-s anda d speci ica ion.
4Excep o he IMS-LD, which has a na a i e app oach in he
con ex o he desc ip ion o pedagogical scena ios.
conside ed a main one). Tha explained ans o ma ion
is encoded in o ules and empla es using he seman ic
abs ac ion o he elemen s o in o ma ion,
concep ually a a highe le el han he syn ac ic
ans o ma ion p o ided by XSLT, allowing ximDEX
o make assump ions and in e ences o gua an ee he
co ec adap a ion o con en s conside ing accessibili y
speci ica ions.
5. Conclusions
We can conclude ha is a key issue o ex end he
IMS speci ica ions o binding all WAI guidelines.
The con e sion o WCAG 1.0 checkpoin s in o
WCAG 2.0 guidelines has inc eased accessibili y
abs ac ion, which can help as a i s s ep o model
hose con en accessibili y p ope ies and lea ne
p o ile in a echnology independen way. I is also
in e es ing o keep in mind ha ex ual in o ma ion is
he linking o ma be ween accessible and no
accessible con en , ac ing as a middlewa e o
accessibili y pu poses. Some imes in o ma ion in a
non- ex o ma can be cap ioned, bu some imes i
mus be jus desc ibed, i.e. i mus be con ex ualized.
So, he e should be p ope suppo o desc ibing
ex ual and con ex ual in o ma ion. One main bene i
o ha app oach would be ha desc ibing con ex
using s anda d seman ic speci ica ions, could
p omo e con en eusabili y, as well as accessibili y.
I could ac as a acili a o o inding con ex ual
issues in a speci ic con en , in a p e ious s ep o he
de-con ex ualiza ion and e-con ex ualiza ion o
con en . The e o e, nex s eps in ximDEX, in o de o
suppo seman ic desc ip ion o con ex , will be o
use he seman ic con en managemen sys em
ximDEX o es ing he bes solu ion be ween hose
discussed in p e ious sec ion, p omo ing also he
in e ope abili y wi h o he con en desc ip ion
speci ica ions: -Using DC Me ada a Se and IMS
Me ada a. -Using he MPEG-7 Seman ic Tool. -
Applying an on ology o ien ed app oach desc ibed in
RDF [17]. The Seman ic CMS ximDEX is al eady
p epa ed o es ing ha solu ion ia he desc ip ion
o he con ex o e e y elemen o in o ma ion
h ough an on ology. Also, he p esen a ion laye can
be managed ia a isualiza ion on ology. We will
also es he easibili y o using ACCMD (o an
ex ended speci ica ion de eloped by us o ying o
co e WCAG).
Re e ences
1. h p://www.w3.o g/TR/1999/WAI-WEBC
ONTENT-19990505/ ull-checklis N.
2. h p://www.w3.o g/TR/2004/WD-WCAG 20-
20041119
3. h p://www.xime ix.com/p oduc os/ximD EX
4. J. A. P ie o, J. Villa , D. Gómez, M. Es ellés,
“Seman ic Managemen o Web Con en s using
ximDEX” (in Spanish), P oc. I Open Sou ce
Wo ld Con e ence, Málaga, Spain, Feb. 2004.
5. IMS AccessFo All Me ada a O e iew,
www.imsp ojec .o g
6. IMS AccessFo All In o ma ion Model,
www.imsp ojec .o g
7. IMS AccessFo All Bes P ac ice and
Implemen a ion Guide, www.imsp ojec .o g
8. Web Con en Accessibili y Guidelines 2.0
www.w3c.o g
9. Dublin Co e Me ada a Ini ia i e, dublinco e.o g
10. CEN-ISSS LTW APLR, www.cen-apl .o g
11. IMS Lea ning Design www.imsp ojec .o g
12. IMS Simple Sequencing, www.imsp ojec .o g
13. Duncan, C: G anula isa ion, Reusing online
esou ces: A sus ainable app oach o e-lea ning,
2003, Chap e 2, ISBN: 0749439491
14. Manjuna h, B.S.(ed): In oduc ion o MPEG 7:
Mul imedia Con en Desc ip ion Language, John
Wiley & Sons, ISBN: 0471486787
15. R. Mohan, J. Smi h, C.-S. Li: Adap ing
Mul imedia In e ne Con en Fo Uni e sal
Access, IEEE T ansac ions on Mul imedia,
Ma ch 1999, pp. 104-114.
16. Whi e Pape : IBM T anscoding Solu ion and
Se ices
17. h p://www.w3.o g/RDF/
DC-2005: P oc. In . Con . on Dublin Co e and Me ada a Applica ions 2005 77