Richard E. Ladner
6/1/2006
Images on the web come in two categories that are easily distinguishable: images that are used to convey content and images that are used for decorative or structural purposes. We call these images significant images and insignificant images, respectively. It is the significant images that should be accessible to blind users of the web. Blind users of the web typically use screen readers such as Jaws and WindowEyes to access the text on the computer screen using speech synthesis. These products read the alternative text found in the alt, title, and longDesc attributes of html encapsulated images. Thus, if these attributes are provided by the webpage designer, then blind users have some access to the content of images.
For the purposes of this study we defined a significant image to be one containing more than one color and having both width and height greater than 10 pixels. Images that are clickable, either because they are contained within anchor tags or because of defined script events, are also considered significant. A significant image was properly labeled if its associated img tag contains a non-zero length alt, title or longdesc attribute, or if the image is contained in the same anchor (link) tag as additional text.
We have surveyed the 157 computer science departments that are listed in the Taulbee Report, 2005. The first column gives the URL of the department, the second column is the total number of images, the third column is the number of significant images, and the fourth column is the percentage of significant images that are properly labeled. The survey was done June 1, 2006 and does not reflect changes to web pages made after that date. A small number of computer science web pages use Flash, which is a technology for images and other media that is generally not accessible to screen readers. This survey does not consider the use of Flash. Summary statistics show that 55% of all significant images on computer science department homepages have alternative text and 20% of all departments had 100% of their significant images with alternative text.
As can be seen from the data there are many homepages that have insignificant images. Not shown is that about 16% of homepages have alternative text for insignificant images, like “space” for a small image that is just filler. These insignificant images should probably not have alternative text.
This survey was done in the spirit of helping departments improve the accessibility of their homepages and websites. I hope to do this same survey on a yearly basis and note the improvements. There are several resources listed below that are useful for webpage designers to make their web pages accessible. Should a webpage design firm be employed, it is would be important to check that they follow accessibility guidelines. Check web pages for comprehensive accessibility using the Bobby or FAE tools referenced below.
W3C: Web Accessibility Initiative, 2006. http://www.w3c.org/wai/.
Functional Accessibility Evaluator. http://fae.cita.uiuc.edu/
J. Thatcher, P. Bohman,
M. Burks, S. L. Henry, B. Regan, S. Swierenga, M. D. Urban, and C. D. Waddell. Constructing Accessible Web Sites.
Glasshaus Ltd.,
J.M. Slatin
and S. Rush.
Maximum
Accessibility: Making Your Web Site More Usable for Everyone. Addison-Wesley
Professional.
J. Clark. Building
Accessible Websites. New Riders, Peachpit Press.
Results of June 1,
2006 Survey of Image Accessibility for Computer Science Homepages (ordered by
percentage of significant images labeled correctly).
|
Total |
Sig |
SigLabel |
Percent |
|
|
www.cis.upenn.edu/ |
34 |
19 |
19 |
100% |
|
www.cc.gatech.edu/ |
19 |
18 |
18 |
100% |
|
www.cs.iit.edu/ |
15 |
15 |
15 |
100% |
|
www.cs.duke.edu/ |
10 |
10 |
10 |
100% |
|
www.ics.uci.edu/ |
8 |
8 |
8 |
100% |
|
www.cse.ohio-state.edu/ |
7 |
7 |
7 |
100% |
|
www.cs.colorado.edu/ |
7 |
7 |
7 |
100% |
|
www.ics.hawaii.edu/IndexServlet |
7 |
7 |
7 |
100% |
|
www.cs.uiowa.edu/ |
6 |
6 |
6 |
100% |
|
www.cs.umn.edu/ |
13 |
5 |
5 |
100% |
|
www.cs.berkeley.edu/ |
7 |
4 |
4 |
100% |
|
www.cs.olemiss.edu/ |
4 |
4 |
4 |
100% |
|
www.du.edu/cs/ |
4 |
4 |
4 |
100% |
|
www.cs.brandeis.edu/ |
3 |
3 |
3 |
100% |
|
www.cs.nmsu.edu/CSWS/php/db.php |
2 |
2 |
2 |
100% |
|
cis.poly.edu/ |
2 |
2 |
2 |
100% |
|
www.cs.clemson.edu/ |
16 |
15 |
15 |
100% |
|
www.uwyo.edu/ |
13 |
12 |
12 |
100% |
|
www.gc.cuny.edu/index_red_buttons.htm |
43 |
39 |
39 |
100% |
|
www.cs.cornell.edu/ |
227 |
72 |
72 |
100% |
|
www.cs.utsa.edu/index.html |
51 |
28 |
28 |
100% |
|
www.cs.northwestern.edu/ |
25 |
12 |
12 |
100% |
|
school.eecs.wsu.edu/ |
41 |
14 |
14 |
100% |
|
www.cs.colostate.edu/ |
8 |
3 |
3 |
100% |
|
www.cs.indiana.edu/ |
20 |
7 |
7 |
100% |
|
www.cs.washington.edu/ |
39 |
13 |
13 |
100% |
|
www.cse.seas.wustl.edu/ |
17 |
3 |
3 |
100% |
|
www.ccs.neu.edu/ |
66 |
7 |
7 |
100% |
|
www.cs.ttu.edu/ |
8 |
7 |
7 |
100% |
|
www.cs.uidaho.edu/csweb/ |
5 |
5 |
5 |
100% |
|
www.cs.rpi.edu/ |
18 |
3 |
3 |
100% |
|
www.cs.tamu.edu/ |
1 |
1 |
1 |
100% |
|
www.cs.ucsb.edu/ |
1 |
1 |
1 |
100% |
|
www.cse.ucsd.edu/index.php |
74 |
32 |
31 |
97% |
|
www.ohio.edu/eecs/ |
34 |
29 |
28 |
97% |
|
www.cs.unc.edu/ |
22 |
22 |
21 |
95% |
|
www.cse.uta.edu/ |
19 |
19 |
18 |
95% |
|
www.csc.ncsu.edu/ |
17 |
15 |
14 |
93% |
|
www.cs.umaine.edu/ |
15 |
14 |
13 |
93% |
|
www.eas.asu.edu/~csedept/index.php |
25 |
12 |
11 |
92% |
|
www.cse.msstate.edu/ |
110 |
101 |
91 |
90% |
|
cs.ua.edu/ |
14 |
9 |
8 |
89% |
|
www.cs.missouri.edu/ |
17 |
9 |
8 |
89% |
|
www.cs.uoregon.edu/ |
8 |
8 |
7 |
88% |
|
www.eecs.ku.edu/ |
8 |
7 |
6 |
86% |
|
www.cs.utexas.edu/ |
33 |
13 |
11 |
85% |
|
www.cs.uah.edu/ |
62 |
61 |
51 |
84% |
|
www.cs.vt.edu/site_pages/home/ |
42 |
42 |
35 |
83% |
|
www.cse.ogi.edu/ |
47 |
17 |
14 |
82% |
|
www.cse.unr.edu/ |
5 |
5 |
4 |
80% |
|
www.cs.iastate.edu/ |
5 |
5 |
4 |
80% |
|
www.cis.ksu.edu/ |
24 |
24 |
19 |
79% |
|
www.cs.mtu.edu/ |
29 |
28 |
22 |
79% |
|
www.eng.auburn.edu/comp/ |
31 |
23 |
18 |
78% |
|
www.cse.uconn.edu/ |
30 |
18 |
14 |
78% |
|
www.cs.depaul.edu/news/default.asp |
14 |
9 |
7 |
78% |
|
www.cis.fiu.edu/home.php |
44 |
30 |
23 |
77% |
|
www-cs.stanford.edu/ |
4 |
4 |
3 |
75% |
|
www.cs.umass.edu/ |
26 |
4 |
3 |
75% |
|
www.cs.brown.edu/ |
4 |
4 |
3 |
75% |
|
www.cs.rochester.edu/ |
4 |
4 |
3 |
75% |
|
www.eecs.mit.edu/ |
5 |
4 |
3 |
75% |
|
www.cs.ucdavis.edu/ |
4 |
4 |
3 |
75% |
|
csce.uark.edu/ |
46 |
22 |
16 |
73% |
|
www.cs.umr.edu/ |
17 |
11 |
8 |
73% |
|
www.cs.virginia.edu/ |
9 |
7 |
5 |
71% |
|
www.cs.purdue.edu/ |
10 |
10 |
7 |
70% |
|
www.cse.msu.edu/ |
34 |
13 |
9 |
69% |
|
www.cs.utep.edu/ |
3 |
3 |
2 |
67% |
|
www.cse.sc.edu/ |
34 |
6 |
4 |
67% |
|
www.cs.fsu.edu/ |
12 |
12 |
8 |
67% |
|
www.cs.dartmouth.edu/ |
3 |
3 |
2 |
67% |
|
www.cs.gsu.edu/ |
4 |
3 |
2 |
67% |
|
www.cs.uwm.edu/ |
8 |
3 |
2 |
67% |
|
compsci.rice.edu/ |
94 |
35 |
23 |
66% |
|
www.cse.ucsc.edu/ |
42 |
31 |
20 |
65% |
|
www.cs.uchicago.edu/ |
11 |
11 |
7 |
64% |
|
www.cis.udel.edu/ |
14 |
11 |
7 |
64% |
|
www.cs.wisc.edu/ |
54 |
19 |
12 |
63% |
|
www.cs.cmu.edu/ |
60 |
38 |
24 |
63% |
|
www.ececs.uc.edu/ |
12 |
8 |
5 |
63% |
|
www.cs.uga.edu/ |
112 |
23 |
14 |
61% |
|
www.cse.psu.edu/ |
6 |
5 |
3 |
60% |
|
www.cs.pdx.edu/ |
11 |
5 |
3 |
60% |
|
eecs.vuse.vanderbilt.edu/ |
12 |
12 |
7 |
58% |
|
www.cs.jhu.edu/ |
29 |
25 |
14 |
56% |
|
www.egr.vcu.edu/cs/index.html |
19 |
18 |
10 |
56% |
|
www.cs.arizona.edu/ |
12 |
11 |
6 |
55% |
|
www.cs.wright.edu/ |
24 |
4 |
2 |
50% |
|
www.cs.unlv.edu/ |
2 |
2 |
1 |
50% |
|
www.cs.wpi.edu/ |
5 |
4 |
2 |
50% |
|
www.eecs.harvard.edu/index/eecs_index.php |
33 |
4 |
2 |
50% |
|
www.cs.rutgers.edu/ |
4 |
4 |
2 |
50% |
|
www.eecs.cwru.edu/ |
2 |
2 |
1 |
50% |
|
www.cs.unomaha.edu/ |
4 |
4 |
2 |
50% |
|
www.cs.uh.edu/ |
19 |
19 |
9 |
47% |
|
ccs.njit.edu/ |
159 |
44 |
20 |
45% |
|
www.louisiana.edu/Academic/Sciences/CMPS/ |
11 |
11 |
5 |
45% |
|
www.cs.caltech.edu/ |
20 |
20 |
9 |
45% |
|
cs.nyu.edu/csweb/index.html |
11 |
9 |
4 |
44% |
|
www.cs.fit.edu/ |
27 |
18 |
8 |
44% |
|
www.cs.drexel.edu/ |
14 |
14 |
6 |
43% |
|
www.eecs.ucf.edu/ |
7 |
7 |
3 |
43% |
|
www.cs.buffalo.edu/ |
62 |
10 |
4 |
40% |
|
www.cs.uiuc.edu/ |
26 |
5 |
2 |
40% |
|
www.usf.edu/index.asp |
34 |
32 |
12 |
38% |
|
www.binghamton.edu/ |
79 |
52 |
19 |
37% |
|
www.cs.ou.edu/ |
11 |
11 |
4 |
36% |
|
cse.unl.edu/ |
79 |
11 |
4 |
36% |
|
www.cs.umbc.edu/CSEE/index.html |
95 |
43 |
15 |
35% |
|
www.cise.ufl.edu/ |
8 |
6 |
2 |
33% |
|
www.csee.umkc.edu/ |
50 |
38 |
12 |
32% |
|
eas.uccs.edu/ |
21 |
17 |
5 |
29% |
|
www.cs.gwu.edu/ |
17 |
17 |
5 |
29% |
|
www.cs.utah.edu/ |
7 |
7 |
2 |
29% |
|
www.cs.yale.edu/ |
26 |
18 |
5 |
28% |
|
www.cs.unt.edu/index.php |
33 |
18 |
5 |
28% |
|
www.cs.utk.edu/ |
106 |
46 |
12 |
26% |
|
www.cs.unh.edu/ |
4 |
4 |
1 |
25% |
|
www.cs.odu.edu/ |
101 |
37 |
8 |
22% |
|
www.cs.princeton.edu/ |
5 |
5 |
1 |
20% |
|
cse.secs.oakland.edu/CSEWEB/ |
43 |
27 |
5 |
19% |
|
www.cs.unm.edu/ |
6 |
6 |
1 |
17% |
|
www.cs.usc.edu/ |
44 |
14 |
2 |
14% |
|
www.cse.lehigh.edu/ |
26 |
15 |
2 |
13% |
|
appserv.pace.edu/execute/page.cfm |
94 |
46 |
6 |
13% |
|
www1.cs.ucr.edu/ |
100 |
32 |
4 |
13% |
|
www.cs.bu.edu/ |
33 |
21 |
2 |
10% |
|
www.cs.umb.edu/ |
15 |
15 |
1 |
7% |
|
www.cs.ucla.edu/ |
77 |
30 |
2 |
7% |
|
www.eecs.umich.edu/ |
21 |
19 |
1 |
5% |
|
www.cs.umd.edu/ |
61 |
3 |
0 |
0% |
|
www.mcs.kent.edu/ |
5 |
1 |
0 |
0% |
|
www.cudenver.edu/Academics/Colleges/ College+of+Engineering+and+Applied+ Science/Computer+Science+Engineering/default. |
96 |
95 |
0 |
0% |
|
www.cs.stevens.edu/ |
78 |
55 |
0 |
0% |
|
www.cs.utdallas.edu/ |
41 |
34 |
0 |
0% |
|
bit.csc.lsu.edu/ |
34 |
31 |
0 |
0% |
|
www.ecs.syr.edu/ |
54 |
20 |
0 |
0% |
|
www.cs.sunysb.edu/ |
17 |
14 |
0 |
0% |
|
www.cs.wayne.edu/ |
13 |
12 |
0 |
0% |
|
engr.smu.edu/ |
30 |
8 |
0 |
0% |
|
www.cse.nd.edu/ |
8 |
8 |
0 |
0% |
|
www.cis.uab.edu/ |
8 |
4 |
0 |
0% |
|
www.cs.tufts.edu/ |
4 |
4 |
0 |
0% |
|
www.cs.uky.edu/ |
24 |
3 |
0 |
0% |
|
www1.cs.uic.edu/CSweb/public/home.php |
9 |
3 |
0 |
0% |
|
www.cs.uml.edu/ |
6 |
3 |
0 |
0% |
|
www.cs.columbia.edu/ |
3 |
3 |
0 |
0% |
|
www.mcs.utulsa.edu/ |
3 |
3 |
0 |
0% |
|
www.cs.usu.edu/ |
8 |
2 |
0 |
0% |
|
www.cs.wm.edu/cspages/ |
3 |
2 |
0 |
0% |
|
www.mines.edu/Academic/macs/ |
2 |
2 |
0 |
0% |
|
cs.gmu.edu/ |
2 |
2 |
0 |
0% |
|
www.cs.ndsu.nodak.edu/ |
2 |
2 |
0 |
0% |
|
www.cs.wmich.edu/ |
2 |
2 |
0 |
0% |
|
www.cs.montana.edu/ |
1 |
1 |
0 |
0% |
|
www.cs.pitt.edu/ |
1 |
1 |
0 |
0% |