ASTER—Towards Modality-Independent Electronic Documents

• Authors: T. V. Raman
• Venue: Multimedia Tools and Applications
• Year: 1998

The advent of electronic documents and the consequent creation of digitallibraries—vast repositories of electronic information—has a profound impact on how we produce, organize, store, retrieve and consumeinformation. All of these activities have been dictated to the present bythe technologies used to share information. A change in the underlyingtechnology, namely, the move from paper to electronic documents, offers aunique opportunity to revolutionize how information is archived anddisseminated. This paper will focus on a specific aspect of theopportunities opened up by electronic publishing on the NII—theability to present information in multiple modalities and thereby free itfrom any single presentation medium.Traditional printed communication relies on a passive intermediary,paper, for the exchange of information between the author and reader. Ideasput down on paper come back to life only when perused by the reader.Electronic publishing is mediated by a computer, an agent capable ofprocessing the information. As a consequence, the ideas expressed by anauthor need no longer be bound to any single “display” form; nordoes it require human intervention to translate the information from onedisplayed form to another. Electronic information can be processed anddisplayed in a manner best suited to each individual‘s needs. Thus, theadvent of electronic documents makes information available in more than itsvisual form—electronic information can now be display-independent.Traditionally, an electronic document has been viewed simply as digitallyrepresenting (or the means towards producing) the printed page. Instead, weview the electronic document as the basic entity that representsinformation; we allow the information to be rendered in differentways—on paper, spoken, processed in different ways by a computer, etc.This change of viewpoint has allowed us to develop ASTER (Audio System ForTechnical Readings) a computing system that audio formats electronicdocuments to produce audio documents. ASTER can speak both literary textsand highly technical documents that contain complex mathematics. Moreover,the listener can ask to have parts of a document repeated in different ways:a document has many different spoken views.The adequacy of the audio rendering depends on how well the electronicdocument captures the essential internal structure of the information. Inthis paper, we discuss capturing structure and give guidelines for authorsto follow to ensure that their documents exhibit structure adequately.In the context of the NII, the digital libraries of the future can beviewed as large information servers that allow multiple clients to accessand display information in a format chosen by the user. By obviating theneed to move physical media, e.g., printed paper or recorded tapes, the NII enables the ready dissemination of multimodal renderings of information.