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.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-04192004-155229 |
| Date | 20 April 2004 |
| Creators | Zeng, Xiaoming |
| Contributors | Bambang Parmanto, Valerie J.M. Watzlaf, Miriam F. Hertz, Ronald E. LaPorte |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-04192004-155229/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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