Zeng, Xiaoming
(2004)
Evaluation and Enhancement of Web Content Accessibility for Persons with Disabilities.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Web content accessibility is to which degree a site is accessible to the largest possible range of people, especially for persons with disabilities. The current study comprises four interrelated parts revolving around evaluating and enhancing Web content accessibility.First, a novel measurement metrics called Web Accessibility Barriers (WAB) score is constructed based on published Web accessibility design guidelines. The performance of the measurement metrics is assessed using a Web accessibility gold standard. The Receiver Operating Characteristic (ROC) curve shows that WAB score separate inaccessible Web pages well from accessible ones with Area Under the Curve (AUC) value of 0.917.Second, using the WAB score, I evaluate the degree of Web accessibility of consumer health information websites. Mean of WAB score of the 108 selected websites is 9.31 with standard deviation of 6.29. Among those websites, government and education websites have lower WAB score - 0.39 and 1.16 respectively. ANalysis Of VAriance (ANOVA) test shows statistical significances across different functional categories of the websites (F=9.705, p < 0.001). In addition, this study shows that WAB score correlated with traffic rank of the websites with (r = 0.32, p < 0.01).Third, a usability study is conducted to examine the performance of a Web Transcoder Gateway (WTG) server for blind Web users to access online information. The WTG server removes Web accessibility barriers in real time based on Web accessibility design guidelines. The study design is a within-subject cross-over design. A mixed model analysis is employed to examine the effect of the WTG server on time, success, errors, and subjective measurement. Sixteen blind Web users took part in the study. Results show that participants spent less time, make few errors, and succeed more on the tasks via WTG server. Participants also feel more satisfactory, less frustrated, and more confident when access online information via WTG server. Observational and anecdotal findings imply that only removing accessibility barriers may not be sufficient to achieve the best usability for blind Web users.Finally, a usability study is conducted to examine the performance of a Web Transcoder Gateway (WTG) server for PDA users to access Web sites. The study design is also a within-subject cross-over design. A mixed model analysis is employed to examine the effect of WTG server on time, success, and subjective measurements. Twenty subjects took part in the study. Results show that participants spend less time on each task via WTG server. Each participant can finish the tasks successfully via either WTG server or non WTG server. This implies that the WTG server can serve as "Electronic Curb Cut" for Web users under constraints. However, the participants show no statistically significant preference to WTG server.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
20 April 2004 |
| Date Type: |
Completion |
| Defense Date: |
16 April 2004 |
| Approval Date: |
20 April 2004 |
| Submission Date: |
19 April 2004 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Health and Rehabilitation Sciences > Rehabilitation Science |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
blind; disability study; human computer interaction; Persons with disabilties; usability; usability testing; web accessibility measurement; Web content accessibility; website design |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-04192004-155229/, etd-04192004-155229 |
| Date Deposited: |
10 Nov 2011 19:38 |
| Last Modified: |
15 Nov 2016 13:40 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/7311 |
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