Generating transformational annotation for web document adaptation: tool support and empirical evaluation

Web annotation is crucial for providing machine-understandable descriptions of Web resources, and has a number of applications such as discovery, qualification, and adaptation of Web documents. While annotations are often embedded into a Web document, annotations can be associated externally by means of addressing expressions represented with the XPath language. However, creation of external annotation solely with a conventional editor is not easy because annotation authoring involves the maintenance and elaboration of addressing expressions as well as annotation contents. In addition, there has been little empirical study of robust pointing by XPath expressions, in spite of the increasing prevalence of the XPath language for use in emerging content adaptation systems. This paper proposes a classification of annotation tool design, taking account of differences in authoring methods and roles of annotation. On the basis of the classification, tools for generating external annotations are briefly explained along with applications of Web document adaptation for small-screen devices and portal site development. Robustness of the addressing expressions is then investigated, and practical implications to the reliable use of external annotation are drawn from empirical evaluation with evolving real-life Web documents.