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Abstract and Figures

The Web Accessibility Quantitative Metric (WAQM) aims at accurately measuring the accessibility of web pages. One of the main features of WAQM among others is that it is evaluation tool independent for ranking and accessibility monitoring scenarios. This article proposes a method to attain evaluation tool independence for all foreseeable scenarios. After demonstrating that homepages have a more similar error profile than any other web page in a given web site, 15 homepages were measured with 10,000 different values of WAQM parameters using EvalAccess and LIFT, two automatic evaluation tools for accessibility. A similar procedure was followed with random pages and with several test files obtaining several tuples that minimise the difference between both tools. One thousand four hundred forty-nine web pages from 15 web sites were measured with these tuples and those values that minimised the difference between the tools were selected. Once the WAQM was tuned, the accessibility of 15 web sites was measured with two metrics for web sites, concluding that even if similar values can be produced, obtaining the same scores is undesirable since evaluation tools behave in a different way.
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This!is!the!author!copy!of!Tool!Independence!for!the!Web!Accessibility!Quantitative!Metric.!Disability!
&!Rehabilitation:!Assistive!Technology!4(4),!248"263.!Informa!Healthcare.!Available!at!
http://informahealthcare.com/doi/abs/10.1080/17483100902903291!
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4 Available at http://www.wabcluster.org/
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Figure!1.!Ideal!hyperbole!that!discriminates!
failure!rates!close!to!0!
!
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Figure!2.!An!approach!to!the!hyperbole!depicted!
in!Figure!1!
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!
%
%for i n each checkpoint in a guideline {P,O,U,R} loop
for j in each type of checkpoint {automatic, warning} loop
for k in each priority{1,2,3} loop
x'=calculate_x'_point(a,b)
if (failure_rate(e,t)<x’) then
Aijk=calculate_S_line(b, e ,t)
else
Aijk=calculate_V_line(a, e, t)
end loop
(1)
ijk
k
kij AwA
=
×=
3
1
end loop
(2)
i
j
ijij
iN
AN
A
×
=
end loop
(3)
N
AN
Ai
ii
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J! C7&#''3! >@&!
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)__( 4
nsamplesofnumberO×
J! H)1;&! a! #17! b! I#$#4&>&$:! #$&! ;+1>)16+6:! >@&3! @#=&!
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)1!+>@&$!S+$7:!>@&!=#'6&!+?!nJ!N@&!4&>@+7!):!I&$?+$4&7!#:!?+''+S:^!
,J G):;$&>)X&!
[ ]
100..0a
! #17!
[ ]
1..0b
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[ ]
95..5a
!S)>@!#! :>&I! +?!,E! 61)>:! :+!>@&$&! #$&! ,E! =#'6&:!QU-! ,U-! 2U-JJ-!ZUR! #17!
[ ]
95.0..05.0b
! S)>@! #! :>&I! +?! EJ,! 61)>:! +9>#)1)1*! #1+>@&$! ,E! =#'6&:! QEJEU-!
EJ,U-JJ-EJZUR!
2J H&'&;>!#! :#4I'&!+?! S&9! I#*&:! ?$+4! 7)??&$&1>! S&9! :)>&:J! q$&?&$#9'3! S&9! I#*&:!
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! !
!for i from 5 to 95 (step 10) loop
for j from 0.5 to 0.95 (step 0.1) loop
for k from 5 to 95 (step 10) loop
for l from 0.5 to 0.95 (step 0.1) loop
for m in all_samples loop
results_ea(m)=WAQM_with_EvalAccess(m,i,j)
results_lift(m)=WAQM_with_LIFT(m,k,l)
end loop
calculate_mean(results_ea)
calculate_mean(results_lift)
end loop
end loop
end loop
end loop!
Proving%the%validity%of%the%sample%
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S)>@!WCDN!Q'&?>R!#17!V=#'5;;&::!Q$)*@>RJ!
!
!
!
Figure!3.!Histograms!for!a!parameter!
Figure!4.!Histograms!for!b!parameter!
!
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:4#''!QZt!#17!it!$&:I&;>)=&'3RJ!5:! #! $&:6'>-! S@&1!'++%)1*!#>!>@&!>6I'&:! >@#>! 4)1)4)X&!
>@&!7)??&$&1;&:-!>@&!?#;>+$! @+4&! I#*&_$#17+4! 7+&:!1+>!I'#3! #13! $+'&! ?+$!V=#'5;;&::J!
517!&=&1!)?!>@&$&! #$&! 7)??&$&1;&:!?+$!WCDN-!>@&3!#$&!$&'#>)=&'3!:4#''J!H)4)'#$!$&:6'>:!#$&!
+9>#)1&7!)?!$&:6'>:!#$&!$&:>$);>&7!>+!>@&!9+>>+4!Ut!I&$;&1>)'&!+?!>@&!7#>#!S)>@!$&:I&;>!
>+!diffJ!
/&:)7&:-!)>!;#1!9&!;+1;'67&7! ?$+4! >@&:&! 7#>#! >@#>!9&:>!;+49)1#>)+1:!>+!4)1)4)X&! diff!
#17!7)??&$&1;&:!9&>S&&1!>++':!#$&^!
aLIFTkYU!-%bLIFTkEJ,U,!aEvalAccesskYU!#17%bEvalAccesskEJ,U!
aLIFTkiU!-%bLIFTkEJEU,!aEvalAccesskiU!#17%bEvalAccesskEJEU!
Observing%the%Behaviour%of%a%and%b%
T1;&!>@#>!>@&!,U!@+4&I#*&:!:#4I'&!S#:!=#')7#>&7-!>@&!#'*+$)>@4!>+!;+4I6>&!WAQM!
S)>@! V=#'5;;&::! #17! WCDN! ;#1! 9&! $61J! C1! #77)>)+1-! S&! ;#1! #':+! #1#'3:&! $&:6'>:! #17!
+9:&$=&!@+S! I#$#4&>&$:! a! #17! b!9&@#=&! S)>@!9+>@! >++':! )1! +$7&$! >+!617&$:>#17! >@&!
$+'&!>@&:&!I#$#4&>&$:!I'#3!>@$+6*@+6>!>@&!S@+'&!$#1*&!+?!=#'6&:J!H)1;&!>@&!I$+;&::!):!
A6)>&! >)4&! ;+1:64)1*-! $&4+=)1*! $#1*&:! +?! =#'6&:! >@#>! 7+! 1+>! )1?'6&1;&! +1! >@&! ?)1#'!
$&:6'>! ):! 6:&?6'! )1! +$7&$! >+! :#=&! >)4&! >@&! 1&[>! >)4&! I#$#4&>&$:! #$&! >61&7! ?+$! #! 1&S!
>++'J!T1;&!#*#)1-!:&'&;>)1*!>@&!>6I'&:!93!$&:>$);>)1*!>+!>@&!,t!I&$;&1>)'&!S)>@!$&:I&;>!>+!
7)??-!S&!+9>#)1!>@&!$&:6'>:!:@+S1!)1!D)*6$&:!U!#17!iJ!!
!
Figure!5.!Boxplots!corresponding!to!aLIFT,!bLIFT,!aEvalAccess,!bEvalAccess,!diff!and!mean!of!the!WAQM!values!
for!the!15!homepages!calculated!with!EvalAccess!and!LIFT!for!the!1%!of!tuples!containing!the!
smallest!values!of!diff4
N@&! $)*@>4+:>! 9+[! I'+>:! )1! D)*6$&! U! :@+S! >@#>! >@&! $#1*&! +?! 4&#1:! +?! WAQMEvalAccess!
#17! +?! WAQMLIFT!):! rUY-hEs-! #17! >@#>! UEt! +?! >@&! =#'6&:! #$&! ;+1;&1>$#>&7! )1! >@&!
$&'#>)=&'3! :4#''! )1>&$=#'! riU-hEs! Q*)=&1! 93! >@&! ?)$:>! #17! >@)$7! A6#$>)'&:R! ?+$! 9+>@! >++':J!
q#$#4&>&$!a! 7+&:! 1+>!I'#3! #!$&'&=#1>! $+'&! )1! +9>#)1)1*! diff!=#'6&:! >@#>! #$&! ;'+:&! >+!E!
S@&$&#:! b! 7+&:J! C1! ?#;>-! aLIFT! #17! aEvalAccess%:I#1! #! $&'#>)=&'3! '#$*&! $#1*&J! bLIFT! #17!
bEvalAccess%:I#1! >@&! &1>)$&! $#1*&-! 96>! S@)'&! >@&! ?+$4&$! ):! ;+1;&1>$#>&7! )1! >@&! $#1*&!
rEJUU-EJZUs! S)>@! #! 4&#1! +?! EJhE-! >@&! '#>>&$! ;+1;&1>$#>&:! )1! rEJMU-! EJFUs! S)>@! #! 4&#1!
&A6#'!>+!EJUZJ!
5II$+I$)#>&! =#'6&:! ?+$! a% #17! b% #$&! >@&! 4&#1! =#'6&:! +?! &#;@! =#$)#9'&^! aLIFTkUF-%
bLIFTkEJhE,!aEvalAccesskYF!#17%bEvalAccesskEJUZJ!5!4+$&!7&>#)'&7!#1#'3:):!+?!>@&!9&@#=)+6$!+?!
bLIFT!#17!bEvalAccess!S@&1!diff!*&>:!;'+:&!>+!E!;#1!9&!+9:&$=&7!)1!D)*6$&!iJ!
!
!
Figure!6.!Scatter!plot!for!bEvalAccess!(x!axis)!and!bLIFT4(y!axis)!
N@&!:;#>>&$!I'+>!)1!D)*6$&!i! :@+S:! >@&! :@#I&! +?! >@&! $&'#>)+1! 9&>S&&1! bEvalAccess!Q[!#[):R!
#17! bLIFT! Q3! #[):R! S@&1! $&:>$);>&7! >+! >@&! :69:&>:! S@&$&! diff!):! :4#''&$! >@#1! >@&! ,t!
I&$;&1>)'&J! N@&! ;+$$&'#>)+1! >@#>! ;#1! 9&! )7&1>)?)&7! 9&>S&&1! >@&! >S+! =#$)#9'&:! ):!
;+1?)$4&7!93!>@&!HI&#$4#1f:!$#1%!;+$$&'#>)+1!>&:>!$@+!@#:!#!=#'6&!+?!EJhi!S)>@!QIl2J2e
,iRJ! N@6:-! &=&1! )?! >@&! >S+! =#$)#9'&:! #$&! 1+>! 7)$&;>'3! ;+$$&'#>&7! >@&$&! ):! #! :>$+1*!
;+$$&'#>)+1!+1!>@&!$#1%:!+?!>@&)$!=#'6&:-!S@);@!&1>#)':!>@#>!>@&3!4+=&!:31;@$+1+6:'3J!
%
Using%Test%Files%
C1!+$7&$!>+!@#=&!4+$&!)1?+$4#>)+1!#9+6>!>@&!&??&;>!+?!>@&:&!I#$#4&>&$:!#17!>+!9&!#9'&!
>+!:&'&;>! >@&! 9&:>! =#'6&:!>@&! :#4&! >61)1*!I$+;&76$&! S#:! ?+''+S&7!6:)1*! #! :&>!+?! >&:>!
?)'&:J!N@&:&!>&:>!?)'&:!@#=&!#!I$&e7&>&$4)1&7!?#)'6$&!$#>&^!!
Low%Accessibility%level%web%page% (LA)! ;+1>#)1:! )4#*&:!S)>@+6>!>&[>!&A6)=#'&1>-!
>#9'&:! S)>@+6>! :644#$3-! :+4&! ')1%:! S@);@! +I&1! I+Ie6I! S)17+S:-! #6>+e
$&?$&:@)1*!#17!)1;+$$&;>!7+;64&1>!'#1*6#*&!7&?)1)>)+1J!
Accessible%web%page%(A)!;+1>#)1:!>@&!:#4&!&'&4&1>:!#17!#>>$)96>&:!96>!>@&3!7+!
1+>! ;#6:&! #13! #;;&::)9)')>3! &$$+$^! )4#*&:! @#=&! >&[>! &A6)=#'&1>-! >#9'&:! @#=&!
:644#$3-! ')1%:! 7+! 1+>! +I&1! 1&S! S)17+S:-! >@&$&! ):! 1+! #6>+e$&?$&:@! #17!
'#1*6#*&!):!S&''!7&?)1&7J!
V'&4&1>:!)1! Medium% Accessibility%level% web% page% (MA)! #$&!>@&! :#4&! #:!)1! >@&!
Low%Accessibility!?)'&!96>!@#'?!+?!>@&!I+>&1>)#'!&$$+$:!#$&!#;>6#'!&$$+$:J!
C1!Worse%than%MA-!M_Y!+?!>@&!I$&=)+6:'3!4&1>)+1&7!I+>&1>)#'!&$$+$:!#$&!#;>6#'!
&$$+$:J!
Better% than% MA!):! ;+4I+:&7! +?! >@&! :#4&! &'&4&1>:! 96>! ,_Y! +?! >@&4! @#=&! #1!
#;>6#'!&$$+$J!
Empty% web% page% E% +1'3! ;+1>#)1:! >@&! 1&;&::#$3! :>$6;>6$#'! gN"W! >#*:! S)>@+6>!
#13!;+1>&1>!&'&4&1>J!
5?>&$! #II'3)1*! 9+>@! >++':! >+! >@&! >&:>! ;+''&;>)+1-! #17! ;+4I6>)1*! >@&! ;+$$&:I+17)1*!
WAQM! =#'6&:! ?+$! #''! ;+49)1#>)+1:! +?! a! #17! +?! b,% S&! ?+617! >@#>! 1+1&! +?! >@&! >6I'&:!
3)&'7&7!#!=#'6&!?+$!diff!&A6#':! >+! EJ! g+S&=&$!>@&!9&:>!;+49)1#>)+1:!#$&!>@&!?+''+S)1*!
+1&:^!
aLIFTkU!-%bLIFTkEJEU,!aEvalAccesskFU!#17%bEvalAccesskEJFU!
aLIFTkU-%bLIFTkEJEU,!aEvalAccesskFU%#17%bEvalAccesskEJZU!
H644#$)X)1*-!6:)1*!7)??&$&1>!4&>@+7:!7)??&$&1>!=#'6&:!?+$!a!#17!b!@#=&!9&&1!+9>#)1&7J!
N#9'&!,!:@+S:!>@&:&!=#'6&:!#:!S&''!#:!:+4&!$&4#$%:!#9+6>!>@&)$!?&#>6$&:J!
!
!
!
!
!
!
!
Table!1.!Best!values!for!a!and!b!produced!by!different!methods!
"&>@+7!
aLIFT%
bLIFT%
aEvalAccess%
bEvalAccess%
$&4#$%:!
g+4&I#*&:!
UF!
EJhE!
YF!
EJUZ!
e!
H#4I'&!
YU!
EJ,U!
YU!
EJ,U!
=#'6&:!>@#>!4)1)4)X&!diff!9&>S&&1!>@&!I#*&:!
#17!
EvalAccessLI FT aa
!#17!
EvalAccessLI FT bb
!
iU!
EJEU!
iU!
EJEU!
N&:>!?)'&:!
U!
EJEU!
FU!
EJFU!
1+1&!+?!>@&!>6I'&:!'&#7:!>+!diff!kE!
U!
EJEU!
FU!
EJZU!
H)1;&!$&:6'>:!#$&!A6)>&!;+1>$#7);>+$3-!>@&!,U!S&9!I#*&:!@#=&!9&&1!4&#:6$&7!)1!+$7&$!
>+!+9:&$=&!S@);@!=#'6&:!+9>#)1!>@&!$&:6'>:!>@#>!'&#7!WAQM!>+!9&!>++'!)17&I&17&1>!?+$!
#''!>@&!:;&1#$)+:J!
5!Recalculation!with!new!values!
N@&!#)4!+?!>@&!$&;#';6'#>)+1!):!>+!;+4I#$&!1&S!$&:6'>:!S)>@!>@&!+1&:!+9>#)1&7!)1!()*+!
&>! #'J! 2EEh! S@&$&! HI&#$4#1f:! $#1%)1*! $@+! QjQ,MiMRkEJh,ZR! I$+=&7! >@#>! >@&$&! S#:! #!
:>$+1*!;+$$&'#>)+1!9&>S&&1!=#'6&:!$#1%&7!93!WAQMEvalAccess!#17!WAQMLIFT!6:)1*!ak2E!
#17!bkEJM!?+$!9+>@!>++':J!g+S&=&$!$&:6'>:!S&$&!:+!7)??&$&1>!>@#>!>@&!6:&!+?!>@&!4&>$);!
)1!>@&! P6#')>3! 5::6$#1;&! :;&1#$)+! S#:! ;+1:>$#)1&7! 93! >@&! >++'J! C>! ;#1!9&! +9:&$=&7!)1!
D)*6$&!h!#!4#$%&7! 7)??&$&1;&! 9&>S&&1! >@&4J! 5! 9+[! I'+>! :@+S:! >@&! 7):>$)96>)+1! +?! >@&!
=#'6&:! 93! @)*@')*@>)1*! >@&! 4&7)#1! Q>@&! >@);%! @+$)X+1>#'! ')1&R-! >@&! ,:>! #17! M$7! A6#$>)'&!
Q>@&!9+>>+4!#17!>+I!+?!>@&!9+[R-!#17!>@&!+6>')&$:!Q=#'6&:!9&3+17!>@&!S@):%&$:RJ!C>!;#1!
9&! $&#7)'3! :&&1! >@#>! WAQMEvalAccess! Q>@&! '&?>4+:>! 9+[! I'+>R! ):! 46;@! @)*@&$! >@#1!
WAQMLIFT!Q9+[!I'+>!)1!>@&!;&1>$&R^!4+$&!>@#1!hUt!+?!>@&!I#*&:!&=#'6#>&7!93!WCDN!@#=&!
#1!:;+$&! >@#>! ):! :4#''&$! >@#1!Y2-! S@&$&#:! ?&S&$! >@#1! 2Ut! +?! >@&!I#*&:! &=#'6#>&7! 93!
V=#'5;;&::! @#=&! #! :;+$&! '+S&$! >@#1! UYJ! "&7)#1! =#'6&! ?+$! WAQMEvalAccess!):! iZ-! ?+$!
WAQMLIFT! )>! ):! 2FJ! C1! #77)>)+1! S&! ;#1! :&&! >@#>! >@&! :I$&#7! +?! WAQMEvalAccess! ):! '#$*&$!
>@#1!WAQMLIFT!Q>@&!7):>#1;&!9&>S&&1!>@&!A6#$>)'&:!?+$!WAQMEvalAccess!):!Mh-!S@&$&#:!)>!
):!,i!e!'&::! >@#1! @#'?! e! ?+$! WAQMLIFT!RJ! WAQMEvalAccess!$&#;@&:!,EE-!S@&$&#:!WAQMLIFT!
$&#;@&:!F2c! 9+>@! :>#$>! ?$+4! ,,J! C>! ;#1! 9&! :&&1! )1! $)*@>4+:>!9+[! I'+>!>@#>! UEt!+?! >@&!
I#*&:!@#=&!#! 7)??&$&1;&!
EvalAccessLI FT WAQMWAQMdiff =
!>@#>!')&:! 9&>S&&1! 2h! #17!
Yh!Q4&7)#1kYERJ!
0
10
20
30
40
50
60
70
80
90
100
A_eval A_lift diff
!
Figure!7.!Box!plots!show!the!clear!difference!between!WAQMEvalAccess4(left)4and4WAQMLIFT!(center)4
C1! #77)>)+1-! @):>+*$#4:! )1! D)*6$&! F! #17! D)*6$&! Z! :@+S! >@#>! S@)'&! WAQMEvalAccess!):!
1&*#>)=&'3!:%&S&7!WAQMLIFT!)>!):!I+:)>)=&'3J!
0
50
10 0
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 10 0
!
Figure!8.!Histogram!of!absolute!frequency!of!
WAQMEvalAccess!
0
50
100
150
200
250
300
350
400
450
500
10 20 30 40 50 60 70 80 90 100
!
Figure!9.!Histogram!of!absolute!frequency!of!
WAQMLIFT!
%
Recalculation%of%Results%
N@&!,U!S&9! :)>&:! ;+1>#)1)1*!#! >+>#'! 1649&$! +?!,YYZ! S&9! I#*&:!@#=&!9&&1! 4&#:6$&7!
#*#)1! S)>@! 9+>@! >++':! 96>! $&:>$);>&7! >+! >@&! a! #17! b! =#'6&:! +9>#)1&7! )1! >@&! I$&=)+6:!
:&;>)+1J!`+>! +1'3!:)4)'#$!$&:6'>:!S#1>!>+!9&!I$+76;&7! 96>!S&!#':+!#)4!#>!;@&;%)1*! >@&!
9&@#=)+6$! +?! >@&! 4&>$);! )1! >@+:&! :;&1#$)+:! >@#>! $&A6)$&! #1! +$7)1#'! :;#'&! +?! >@&!
#;;&::)9)')>3!'&=&'J!N@6:-!HI&#$4#1f:!;+$$&'#>)+1:!#$&!#':+!;#';6'#>&7!)1!&#;@!;#:&J!N#9'&!
2!:@+S:! >@#>!>@&!:>$+1*&$!;+$$&'#>)+1!;#1!9&! ?+617!)1!>6I'&!uM!S@&$&!akiU!#17!bkiU-!
jkEJih!QIl2J2e,iR!S@);@!):!#!4+7&$#>&!;+$$&'#>)+1J!N6I'&:!u,!#17!u2!#':+!:@+S!#!:)4)'#$!
9&@#=)+6$! &=&1! )?! >@&! ;+$$&'#>)+1! ):! :')*@>'3! '+S&$J! N6I'&:! ;+$$&:I+17)1*! >+! =#'6&:!
+9>#)1&7! 93! 6:)1*! >&:>! ?)'&:! :@+S! >@&! '+S&$! ;+$$&'#>)+1! S@);@! ):! #$+617! EJUE! Q'+Se
4+7&$#>&R!96>!:>)''!:)*1)?);#1>J!
Table!2.!Tuples!with!a!and!b4values!and!Spearman’s!rank!correlation!as!well!as!data!to!interpret!the!
data!distribution.!Note!that!the!upper!row!in!each!tuple!corresponds!to!EvalAccess!while!the!lower!
one!correspond!to!values!for!LIFT%
>6I'&!
aLIFT%
bLIFT%
aEA%
bEA%
HI&#$4#1!j!Q,YYZR!
4)1!
,:>!P!
"&7)#1!
M$7!P!
4#[!
"&#1!
u,!
UF!
EJhE!
YF!
EJUZ!
EJiY-!Il2J2e,i!
2!
UY!
65!
Z,!
,EE!
iF!
,Y!
UZ!
64!
h2!
ZZ!
iY!
u2!
YU!
EJ,U!
YU!
EJ,U!
EJi,-!Il2J2e,i!
2!
Y2!
i,!
FZ!
,EE!
i,!
,M!
YE!
YF!
iE!
ZF!
YZ!
uM!
iU!
EJEU!
iU!
EJEU!
EJih-!Il2J2e,i!
M!
MY!
UU!
FU!
,EE!
Uh!
,Y!
YM!
YF!
UF!
ZU!
UE!
uY!
U!
EJEU!
FU!
EJFU!
EJU,-!Il2J2e,i!
Z!
Ui!
iZ!
Z,!
,EE!
h,!
,!
,E!
2E!
YY!
ZU!
2i!
uU!
U!
EJEU!
FU!
EJZU!
EJUE-!Il2J2e,i!
,2!
UF!
ih!
Z,!
,EE!
h,!
,!
,E!
,F!
YY!
ZU!
2U!
N@&!>6I'&!>@#>!:@+S:!>@&!4+$&!:)4)'#$!7):>$)96>)+1!9&>S&&1!:>#>):>);#'!=#'6&:!I$+76;&7!
93!WCDN!#17!V=#'5;;&::!):!>@&!;$)>&$)+1!>+!:&'&;>!>@&!4+:>!#7&A6#>&!a!#17!b!I#$#4&>&$:J!
N@&!,:>!A6#$>)'&-!M$7!A6#$>)'&!#17!>@&!4&7)#1!#$&!&:I&;)#''3!;+1:)7&$&7J!H)1;&!>6I'&:!uY!
#17! uU! :@+S! >@#>! >@&:&! =#'6&:! #$&! ;+4I'&>&'3! 7)??&$&1>! >@&3! #$&! 7):;#$7&7J! T1! >@&!
+>@&$!@#17-!)1!>@&!$&:>!+?!>@&!>6I'&:!=#'6&:!*&>!;'+:&$J!!
0
20
40
60
80
100
WAQM_EA WAQM_LIFT diff
!
Figure!10.!Box!plots!for!WAQMEvalAccess4(left)!and!WAQMLIFT4(right)4when!aEA=48,!bEA=0.59,!aLIFT=58!and!
bLIFT=0.70!
N@&$&?+$&-!&)>@&$!+?!>@&4!S+6'7!9&!#II$+I$)#>&!96>!?+$!?6$>@&$!;#';6'#>)+1:!>6I'&!u,!):!
:&'&;>&7!#:!>@&!4&7)#1!):!#'4+:>!>@&!:#4&!#:!;#1!9&!:&&1!)1!D)*6$&!,EJ!C>!;#1!9&!#':+!
+9:&$=&7!>@#>! 1+S!WCDN!+9>#)1:!@)*@&$!=#'6&:!e!4#[kZ,!e!;+4I#$&7!>+!D)*6$&!h!S@&$&!
4#[kF2!#17!diff!4)1)4)X&:!'3)1*!9&>S&&1!i!#17!2YJ!C>!;#1!#':+!9&!7&76;&7!?$+4!D)*6$&!
,E! >@#>! WCDN! =#'6&:! #$&! 4+$&! ;+1;&1>$#>&7! S@);@! ):! ;+1?)$4&7! 93! >@&! @):>+*$#4! )1!
D)*6$&!,2J!
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100
!
Figure!11.!Histogram!of!absolute!frequency!of!
WAQMEvalAccess4when!a=48!and!b=0.59!
0
100
200
300
400
500
600
10 20 30 40 50 60 70 80 90 100
!
Figure!12.!Histogram!of!absolute!frequency!of!
WAQMLIFT4when!a=58!and!b=0.70!
!
B+4I#$&7!>+!>@&!@):>+*$#4:!)1!D)*6$&:!F!#17!Z!>@&!@):>+*$#4:!#9+=&!@#=&!=#'6&:!4+$&!
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WAQMLIFT!@#:!>@&!ZFt!+?!>@&4J%
%
Accessibility%Formulas%for%a%Web%Site%
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Table!3.!Accessibility!scores!obtained!using!different!formulas!for!a!web!site!(mean,!depth)!with!
EvalAccess!and!LIFT!as!well!as!the!difference!between!both!approaches!when!different!tools!are!used!
(diffmean!and!diffdepth).%
!
WAQMEvalAccess%
WAQMLIFT!
diffmean%
diffdepth%
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0
5
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mean depth
!
Figure!13.!Box!plots!for!diffmean!and!diffdepth!
(#'6&:!#$&!4+$&!;+1;&1>$#>&7!?+$!diffmean!Q,:>!PkMJU-!M$7!Pk,,JUR!S@);@!$#1*&:!?$+4!E!
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0
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80
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U of Cambr idge
City U London
U of Kansas
Lanca ster U
U of Niger ia
U of Calga ry
U of Berke ley
The Irish Times
U of Bolton
U of Preto ria
U of Dundee
Belfast Telegraph
Daily Expre ss
Sydney M Herald
Outlook India
EvalAccess
LIFT
!
Figure!14.!Accessibility!scores!obtained!by!different!websites!by!EvalAccess!and!LIFT!using!the!mean!
approach!
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6!Conclusions!
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!
References!
!
r59#:;#'!&>!#'J-!2EEYs!59#:;#'-!8J-!5$$6&-!"J-!D#0#$7+-!CJ-!.#$#3-!`J!#17!N+4n:-!8J!Q2EEYR!<:&!+?!.6)7&')1&:!
>+!56>+4#>);#''3!(&$)?3!O&9!5;;&::)9)')>3J!C1>&$1#>)+1#'!8+6$1#'!+1!<1)=&$:#'!5;;&::!)1!>@&!C1?+$4#>)+1!
H+;)&>3!Q<5CHR!MQ,R-!I#*&:!h,ehZ-!HI$)1*&$J!
r59+6em#@$#-!HJ-!2EEis!59+6em#@$#-!HJ!Q&7JR!Q2EEiR!B+1?+$4#1;&!V=#'6#>)+1!+?!O&9!H)>&:!?+$!
5;;&::)9)')>3J!O&9!5;;&::)9)')>3!C1)>)#>)=&J!5=#)'#9'&!#>!@>>I^__SSSJSMJ+$*_O5C_&=#'_;+1?+$4#1;&J@>4'!
r5$$6&!&>!#'J-!2EEUs!5$$6&-!"J-!()*+-!"J!#17!59#:;#'-!8J!Q2EEUR!P6#1>)>#>)=&!"&>$);:!?+$!O&9!5;;&::)9)')>3!
V=#'6#>)+1J!q$+;&&7)1*:!+?!>@&!O+$%:@+I!+1!O&9!"&>$);:!#17!"&#:6$&4&1>!-!;+e'+;#>&7!#>!>@&!U>@!
C1>&$1#>)+1#'!B+1?&$&1;&!+1!O&9!V1*)1&&$)1*-!CBOV!2EEUJ!<1)=&$:)>3!+?!O+''+1*+1*!H;@++'!+?!CN!#17!
B+4I6>&$!H;)&1;&J!
r5$$6&!&>!#'-!2EEFs!5$$6&-!"J-!()*+-!"J!#17!59#:;#'-!8J!Q2EEFR!O&9!5;;&::)9)')>3!5S#$&1&::!)1!H&#$;@!
V1*)1&:!d&:6'>:J!C1>&$1#>)+1#'!8+6$1#'!+1!<1)=&$:#'!5;;&::!)1!>@&!C1?+$4#>)+1!H+;)&>3!Q<5CHR!hQ,e2R-!I#*&:!
,EMe,,i-!HI$)1*&$J!
r/#)'&3!#17!/6$7-!2EEUs!/#)'&3-!8J!#17!/6$7-!VJ!Q2EEUR!N$&&e"#I!():6#'):#>)+1!?+$!O&9!5;;&::)9)')>3J!2Z>@!
B+4I6>&$!H+?>S#$&!#17!5II');#>)+1:!B+1?&$&1;&-!BT"qH5BfEU-!I#*&:!2hUe2FE-!CVVV!B+4I6>&$!H+;)&>3!
q$&::J!
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r/$#01)%!#17!W+46:;)+-!2EEhs!/$#01)%-!.J!#17!W+46:;)+-!dJ!Q2EEhR!H5"/5^!#!H&4)e56>+4#>);!"&>@+7!?+$!
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... Automated web accessibility tools can generate different results and do not capture all the problems when analysing the homepages. Vigo et al. [55] analysed the use of web accessibility evaluation tools, specifically, the coverage, completeness and correctness with regard to WCAG 2.0 conformance, finding a large number of problems in the three variables analysed. They concluded that the use of automated tests entails that "1 of 2 success Fig. 1 Map of international tourist arrivals and level of conformance AA and AAA by country criteria will not even be analysed and among those analysed, only 4 out of 10 will be caught at the further risk of generating false positives". ...
... Considering the limitations of the use of web accessibility evaluation tools (the focus on homepages produces a similar error profile than any other webpage in a given site) [55], and that TAW only analyzes the home pages, it may be argued that Hong Kong, Japan and South Korea homepages are clear examples of good practices in their websites. They have a very low number of issues in the analysis, compared to other websites. ...
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Various initiatives have been undertaken in recent years to improve the accessibility of tourism in a large number of countries. One of the areas in which work has been done has been the inclusion and accessibility of information for all, especially for people with disabilities and other users with access needs. A focus of this work has been to the digital world, given the increasing relevance of the internet in daily life. This paper aims to determine whether the different nation states are applying appropriate standards, both under their own regulations and under those from United Nations agreements regarding accessibility to online tourism information to foster more sustainable tourism. In the study of official tourism organization website home pages of the countries contained in the World Tourism Organization reports, cluster analysis was used to identify common behaviour patterns. The main result was the need to improve the compatibility and ease of navigation of websites, as well as identifying Japan, Hong Kong and South Korea as countries that can serve as examples of good practice.
... More recently, Vigo et al. proposed a quantitative measurement for Web accessibility called Web Accessibility Quantitative Metric (WAQM) [96,97], to accurately measure the accessibility of Web content. This approach can provide a means for quantifying quality assurance, information retrieval, and monitoring Web accessibility. ...
... It assumes that all Web pages in a Website has equal importance, but this is not true in practice. Thus, in [97], Vigo et al. extended their approach, so that Web pages that are deeper in the hierarchy will have lesser impact on the final value. ...
... V line formula By manipulating parameters a and b it is possible to adapt WAQM to a specific evaluation tool and obtain tool independence. Originally, WAQM was tuned to work jointly with EvalAccess (a = 20, b = 0.3) but Vigo et al. (2009b) proposed a method to tailor a and b to other specific tools. Results show that for scenarios requiring ordinal values (e.g., for ranking purposes) the tuning was not necessary because WAQM proved to be independent of the tool when conducting largescale evaluations (approx. ...
... As a consequence we should expect these differences to reflect on differences on the scores. For example, Vigo et al. (2009b) discuss differences of the WAQM metric when fed with data produced by two different tools. After measuring more than 1300 web pages they found that scores produces by LIFT and EvalAccess evaluation tools were different although there was a strong correlation between the rankings of the scores. ...
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... Currently, the version of the Web Content Accessibility Guidelines (WCAG) has arrived in version 2.0, and 2.1 whose main goal is to determine how to make Web content more accessible to people with disabilities. Accessibility involves a variety of disabilities, including vision, hearing, physical, speech, cognitive, language, learning, and neurological disabilities [9][10][11]. There are many tools that can be used as a guide or guideline in developing website 3 accessibility, such as EvalAccess 2.0, Achecker, TAW, and Watchfire Bobby [1] and also Wave [12], however it is recommended to use WCAG because it is considered to have a more complete and widely used standard in the world. ...
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Abstract. Access to quality education in the era of ICT technology is growing rapidly, by utilizing this technology ideally it is not a problem, thus the presence of technology can be a problem solver that occurs such as inequality of quality educational material and access to the intended materials, this is certainly a dream all parties because, in reality, all this is not easy. The biggest challenge in equalizing the quality of education is experienced by almost all countries in the world, especially countries with large territories and populations. Inequalities and gaps in differences and equal access to quality education material occur in almost every country in the world. Distance learning can be carried out easily by utilizing ICT infrastructure. Almost every country in the world strives to provide open wide access through the use of web-based applications to facilitate and facilitate the population of the needs of teaching materials according to the population. This article will discuss, analyse and explore the comparison of the accessibility of the Open Educational Resources (OER) repository in developed countries with developing countries.
... Moreover, it is reasonable to presume that accessibility issues emerging from the homepage assessment are likely to propagate to other web pages. For example, Vigo et al (2009) demonstrated that homepages have a more similar error profile than any other web page in a given website. Further, the homepage plays the role of the index to other hyperlinked documents within the website and is the façade that shapes the end user's first impression upon visiting a given e-Government portal (Abdul Latif and Masrek, 2010). ...
... Further, it is reasonable to presume that accessibility issues emerging from the homepage assessment are likely to propagate to other web pages. For example, Vigo et al (2009) demonstrated that homepages have a more similar error profile than any other web page in a given web site. Further, the homepage plays the role of the index to other hyperlinked documents within the web site and is the fac¸ade that shapes the end user's first impression upon visiting a given e-government portal (Abdul Latif and Masrek, 2010). ...
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... Even if it would be desirable to define metrics for websites, a study by Nielsen and Tahir [26] states that the usability of the homepage predicts the usability of the whole site. Supporting this statement, Vigo et al. [42] provide empirical data to corroborate such a statement, at least in the context of automatic accessibility measurement. ...
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