Improving accessibility through the visual structure of web contents

Web accessibility has become one of the most popular research targets. Web accessibility means the ability to be accessed by all kinds of people or devices. One problem that some Web pages have rather poor information structures at the HTML source code level, even though the pages are well structured visually. In order to transfer the visual structure to the HTML level structure, we need to identify the graphic design features that influence human understanding. We examined whether several people interpreted a displayed structure in the same way or not. Four subjects participated in trials; they attempted to identify the headers, major items forming the structure of the top page, of the web sites of 7 local governments in Japan. 80 % of the headers were selected by all subjects so most subjects shared the same understanding of what constituted a header.