Lightweight realistic books: the greenstone connection

Realistic physically-based computer models of page-turning have been around for years, but are rarely deployed in practice except as eye-catching demos. This demo shows a connection from the Greenstone digital library system to a lightweight Macromedia Flash-based page turning mechanism that allows books in certain styles of collection to be automatically presented using animated page-turning. The system is reactive: it opens books quicker than Adobe Acrobat does and responds instantly to the user’s mouse gestures. It capitalizes on a particular style of structural metadata shared by many Greenstone collections, and uses metadata to enhance browsing the library’s contents. There are opposing views on whether readers may gain any advantage from using a 3D physical book model. There is enough evidence, both anecdotal and from formal user studies, to suggest that the usual (HTML or PDF) presentation of documents is not always the most convenient, or the most comfortable, for the reader. On the other hand it is quite clear that while 3D physical book models have been prototyped and demonstrated, none are in routine use in today’s DLs. Given the remarkable historical success of the book form, and the fact that the superiority of HTML or PDF presentation is at least questionable, why are physical book models not more widely available in practical digital libraries? We suggest that the answer is not because of any proven drawbacks, but is purely technological. Chu et al. [1] add a realistic book representation to Greenstone. However, although it makes an eye-catching demo the system is not used for actual reading, for several reasons: special “turning the pages” software must be installed on the reader’s computer; the system does not have access to external metadata such as cover images or internal metadata such as section breaks; and it is painfully slow. No doubt these could be ameliorated by improved implementations. However, informal observations of people using digital library collections in many different countries and environments is that even PDF readers are too slow, mainly because of the start-up delay. A different approach is called for if page turning is to be deployed in practice.