Yael Netzer and Michael Elhadad
Dep. of Computer Science, Ben Gurion University, Beer Sheva, Israel
{yaeln, [email protected]
Natural language generation (NLG) refers to the process of
producing text in a spoken language, starting from an internal
knowledge representation structure. Augmentative and
Alternative Communication (AAC) deals with the development
of devices and tools to enable basic conversation for
language-impaired people.
We present an applied prototype of an AAC-NLG system
generating written output in English and Hebrew from a
sequence of Bliss symbols. The system does not “translate”
the symbols sequence, but instead, it dynamically changes
the communication board as the choice of symbols proceeds
according to the syntactic and semantic content of selected
symbols, generating utterances in natural language through a
process of semantic authoring.
Augmentative and Alternative
Communication (AAC)
Augmentative and alternative communication (AAC)
communication that can be added to natural
communication (speech and writing), especially
when an individual lacks some of the skills to
achieve it.
AAC devices are characterized by three aspects
[Hill and Romich, 2002]:
1. Selection method
2. Input language
3. Output medium
In a computerized system [McCoy and Hershberger,
1999], a processing method aspect is added to this
list. This method refers to the process which creates
the output once symbols are inserted.
Blissymbolics (bliss in short) is a graphic
meaning-referenced language, created by
Charles Bliss to be used as a written universal
language. It was first published in 1949 and
elaborated later in 1965 in his book
Semantography [Bliss, 1965]. Bliss, a survivor of
the Holocaust, was infuenced by the Chinese
orthography system and his life experience, and
wished to establish an understandable written
language that could be used by people of
different nations and languages {as he believed
that language misunderstanding is a main cause
of wars in the world.
In 1971, the bliss symbol system was first used
for communication with severely languageimpaired children.
Symbol types of Blissymbols
Ontology fragments of concepts and relations
Indicators modify the lexical category of the symbol
Each time a symbol is chosen, the system converts the
current expression to a conceptual graph (CG), maps the CG
to a FUF Functional Description (FD), which serves as input
to the lexical chooser; lexical choice and syntactic realization
are performed, and feedback is provided in English or
If the chosen symbols so far were I and to play, the
conceptual graph built is:
Modifiiers in Blissymbols
Generation Process (lexical choice and syntactic realization)
This CG is transformed into an FD of the appropriate
form and is unified with the lexical chooser, using the
information on the verb play as embedded in the
concept representation:
<description descriptionNumber="0.2"
secondary="+ with-NP" xtag="0.2"/>
The intransitive structure is chosen since there is
only one participant given, and the resulting string
generated is I play.
However, once Pablo was chosen as the second
actor relation and the CG is complete:
The system consults the lexical chooser again and
unifies the given input with the verb's possible
syntactic structures following its alternation,
in this case:
Alternation alternation-of-verb-playsimple_reci_intrans:
[struct with-np]
This syntactic alternation indicates that the clause:
I play with Pablo can be generated. Alternatively,
following the possible choice of the alternation which
is available for the verb play with its current sense,
the structure (STRUCT SUBJ-AND-NP-V) can be
chosen as well, with the final output Pablo and I
play. In the GUI of the system, a button can switch
the generation of the clause from one argument
structure to the next, according to the alternations
supported by the verb.
Next, the system offers the opportunity to add
sentence modifiers such as time and location and
other possible circumstances.
Various realizations of the verb ‘to be’ in Blissymbols
Selected References
Ofer Biller, Michael Elhadad, and Yael Netzer. 2005. Interactive
authoring of logical forms for multilingual generation.
In Proceedings of the 10th workshop of ENLG, Aberdeen,
Charles K. Bliss. 1965. Semantography (Blissymbolics).
Semantography Press, Sidney.
D. Jeffery Higginbotham. 1995. Use of nondisabled subjects in
AAC research: Confessions of a research infidel. AAC
Augmentative and Alternative Communication, 11, March.AAC
Research forum.
Kathleen F. McCoy and Dave Hershberger. 1999. The role of
evaluation in bringing NLP to AAC: A case to consider. In Filip T.
Loncke, John Clibbens, Helen H. Arvidson, and Lyle L. Lloyd,
editors, AAC: New Directions in Research and Practice, pages
105–122. Whurr Publishers, London.
Kathleen F. McCoy. 1997. Simple NLP techiques for expanding
telegraphic sentences. In Proceedings of workshop on NLP for
Communication Aids, Madrid, July. ACL/EACL.
Pascal Vaillant. 1997. A semantic-based communication system
for dysphasic subjects. In Proc. of the 6th conference on AI in
Medicine Europe (AIME’97), Grenoble, France, March.

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