2012 Volume 20 Issue 1 Pages 11-25
Currently, many universities use Web services, such as SlideShare and edubase, to store presentation files. These files provide varying levels of knowledge, and are useful and valuable to students. However, self-learners retrieving such files still lack support in identifying which slides meet their specific needs. This is because, amongst presentation files intended for different levels of expertise, it is difficult to understand the context, and thus identify relevant information, of a user query in a slide. We describe a novel browsing method for e-learning by generating snippets for target slides. For this, we consider the relevant information between slides and identify the portions of the slides that are relevant to the query. By analyzing the keyword conceptual structure on the basis of semantic relations, and the document structure on the basis of the indent levels in the slides, not only can target slides be precisely retrieved, but their relevant portions can also be brought to the attention of the user. This is done by focusing on portions from either detailed or generalized slides at the conceptual level; this gives the surrounding context to help users easily determine which slides are useful. We also present a prototype system and the results of an evaluation of its effectiveness.