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A Personalisable Electronic Book for Video-based Sign Language ...

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A sign language is not a word-by-word translation of a spoken language, but is a language in its own right. <strong>Sign</strong><br />

languages, such as American <strong>Sign</strong> <strong>Language</strong> (Sternberg M L, 1996) and British <strong>Sign</strong> <strong>Language</strong> (Sutton-Spence<br />

R & Woll B, 1999), differ significantly in their syntax and semantics from American or British English.<br />

There<strong>for</strong>e, the relationship between written English and sign language is very different from the relationship<br />

between written English and spoken English. Written English is a <strong>for</strong>eign language to native speakers of sign<br />

languages. In sign languages movements, body positions and expressions are integral parts of the syntax. These<br />

do not easily translate to written texts. Furthermore, printed text often uses phraseology and grammatical<br />

constructs that make word by word translation difficult, if not impossible (Coleman J R & Wolf E E, 1991). As<br />

a result, printed text must nearly always be translated, by the teacher, into sign language, on behalf of the<br />

student, in real time. This process is expensive in terms of time and teaching resources and requires a high level<br />

of expertise.<br />

One approach to making printed, or WWW-<strong>based</strong>, educational materials accessible to deaf children is to<br />

establish a pictorial representation of the vocabulary and syntax of a sign language. These representations are<br />

called writing systems (Sutton V, 1996). Specifically, sign language writing systems use a set of visually<br />

designed symbols that record how people sign, thereby representing the visual subtleties of sign language.<br />

Although several proposals <strong>for</strong> sign language writing systems have been made (Sutton V, 1997), and tentative<br />

steps have been taken towards providing software-<strong>based</strong> sign language translators such as the <strong>Sign</strong>Writing<br />

Markup <strong>Language</strong>, SWML (da Rocha Costa A C, 2003), to allow <strong>for</strong> the automatic generation of electronic texts<br />

written in sign language, there is still no universally accepted writing system <strong>for</strong> sign languages.<br />

In the absence of a universally accepted writing system, video has emerged as the primary technological<br />

plat<strong>for</strong>m used to present educational material to the deaf. <strong>Sign</strong>ing books (Pragma, 2002) are video presentations<br />

of textual material. They are analogous to talking books <strong>for</strong> the blind. In such books, a narrator is recorded on<br />

videotape while signing the content of the book. The signing may be complemented by subtitles and other visual<br />

clues (i.e., graphics, animations, etc.). As signing books are presented via video, they inherit the inherent<br />

weaknesses of the medium. <strong>Video</strong>tape is inefficient to navigate through: a user must linearly shuttle backwards<br />

and <strong>for</strong>wards through the tape, as no direct access mechanism is available. Furthermore, users are unable to<br />

search <strong>for</strong> a specific phrase or topic. There are no contextual links <strong>for</strong> browsing and no table of contents to<br />

locate particular subjects. Finally, videotape degrades with repeated use. These weaknesses become particularly<br />

evident when such books are used <strong>for</strong> educational purposes.<br />

The deficiencies in videotape technology are a motivating factor <strong>for</strong> our use of hypermedia technologies as a<br />

plat<strong>for</strong>m <strong>for</strong> the delivery of sign language learning materials. The ability of hypermedia systems to make nonlinear<br />

context <strong>based</strong> navigation available to users, through the inclusion of hyperlinks, and their ability to make<br />

use of computational resources to dynamically manage content, suggests that this medium may be a more<br />

appropriate delivery plat<strong>for</strong>m. Furthermore, content accessible via hypermedia systems is stored digitally and is<br />

there<strong>for</strong>e not subject to degradation through repeated use.<br />

In the case of AH, we propose that users could benefit from possibilities, not only related to the medium, but to<br />

the design of the software itself. Adaptive hypermedia technologies are starting to prove effective in per<strong>for</strong>ming<br />

in<strong>for</strong>mation retrieval tasks when users have different in<strong>for</strong>mation seeking goals and histories (Karagiannidis C et<br />

al, 2001; Bajraktarevic N et al, 2003). The ability of these techniques to tailor the content made available on an<br />

individual basis and the ability to adapt this content to the specific knowledge that a user has of a subject could<br />

yield similar advantages to the deaf learner. Furthermore, the ability of adaptive hypermedia systems to tailor<br />

link presentation, in order to direct and assist users in their online learning, appears to make adaptive hypermedia<br />

techniques and technologies good candidates <strong>for</strong> use in the development of sign language education systems.<br />

KSO <strong>Electronic</strong> <strong>Book</strong> Framework and Systems Architecture<br />

In this section, we outline our view of electronic books, and provide an overview of the Goldsmiths Adaptive<br />

Hypermedia Model. This <strong>for</strong>mal model was used as the systems architecture in the design of the KSO adaptive<br />

electronic book.<br />

In this paper, we define the content of an <strong>Electronic</strong> <strong>Book</strong> (E-book) to be a hyperlinked network of digital<br />

in<strong>for</strong>mation units. When these in<strong>for</strong>mation units are rendered, they provide the user with optional links to other<br />

in<strong>for</strong>mation units. A rendering unit in an E-book is viewed as a hyperpage, and a collection of units as a<br />

hypermedia presentation. Such presentations are accessible via a WWW-browser (e.g., Galeon, Firebird,<br />

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