ERCIM News No.26 - July 1996 - FORTH
Access to Lexical Knowledge in Interpersonal Communication Aids
by Constantine Stephanidis and Margherita Antona
The TIDE-ACCESS Project 1001 produces innovative methodologies
and tools for access to computer-based applications by potentially all users,
including people with disabilities. It focuses on the unified creation of
User Interfaces adaptable to different user needs, characteristics and preferences,
and at the same time aims at the design of innovative applications offering
functionalities suitable for the potential target user groups.
One of TIDE-ACCESS project's application domains is Interpersonal Communication
Aids, ie devices enabling people with speaking difficulties to communicate.
Communi-cation aids provide users with a vocabulary display (of either a
natural language or a symbolic language, eg Bliss) and functions for composing
and sending messages. In the framework of ACCESS, an innovative modular
architecture is elaborated facilitating the design of highly tailorable
and adaptable communication aids.
An important aspect of adaptability in communication aids concerns the selection
of an appropriate language and vocabulary set for each user without precluding
communication with users of different languages.
The User Vocabulary and Meaning Mapping Module, designed and implemented
at ICS-FORTH in the context of this project, is a knowledge base containing
lexical information related to symbolic and orthographic languages in Interpersonal
Communi-cation Aids. Its main purpose is to make multilingual knowledge
available both during the configuration of devices and their use for communication.
During configuration, usually performed by a therapist, the Module makes
it possible to consult the vocabularies of already defined symbolic or natural
languages and define new user languages along with their vocabularies. During
communi-cation, it ensures translation between whatever user language at
a lexical level.
The Module is language independent, and is designed in such a way to allow
encoding of any type of linguistic knowledge. Information is represented
by means of a typed feature structure representation language (the ALE,
Attribute Logic Engine, developed at CMU and available for research purposes),
while retrieval, language definition and vocabulary definition functions
are implemented in Prolog.
Currently encoded information includes:
- defined languages and their characteristics (symbolic or orthographic
nature, subset relationship to other defined languages, etc)
- part of speech categories
- a simple domain model for common communication topics like food, family
and people in general, house equipment, weather, etc)
- vocabularies for two ortho-graphic and two symbolic languages (English,
Finnish, Bliss and Pictograms).
Lexical entries in each vocabulary contain features representing parts of
speech and domain model concepts. Retrieval of lexical items takes place
by unification of features structure descriptions. Lexical translational
equivalence between items of all languages is defined as feature value identity
on domain model concepts.
The Module can be further expanded by:
- included languages
- syntactic information
- domain model information and size
- vocabulary information and size.
Future work in the direction of representing and exploiting linguistic information
in communication aids will build on the existing knowledge base to include
parsing, message-to-message translation and other techniques such as word
prediction and other rate-enhancement techniques.
Please contact:
Constantine Stephanidis - ICS-FORTH
Tel: +30 81 391741
E-mail: cs@ics.forth.gr
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