- Symbol - is "something that stands for or
represents something else" (Vanderheiden & Yoder,
- Referent - the "something else" that a symbol
represents is called its referent.
- Iconicity - refers to the continuum that
describes symbols by ease of recognition.
- Transparent - At one end of this iconicity
continuum are transparent symbols, which visually resemble their
referents and thus are high in guessability, and at the other end
are opaque symbols, whose visual relationships to their referents
are not obvious and may be quite arbitrary.
- Translucent - In the middle of the iconicity
continuum are translucent symbols, which are not readily guessable
without additional information. Translucent symbols are often
described in terms of their learnability.
- Aided - symbols require some type of external
assistance such as a device for production. Examples of aided
symbols include real objects and black and white line
- Unaided - symbols require no external device
for production. Examples of unaided symbols include facial
expressions, manual signs, natural speech and vocalizations.
- Pictograph represents the meaning of a word or
concept through a picture; e.g., a photograph, picture or line
drawing of a house to represent house.
- Ideograph represents an idea related to the
word; e.g., a drawing of a heart to represent love or emotion.
- Arbitrary is one to which meaning is assigned;
e.g., Blissymbols uses the symbol / to represent the.
- Tangible Symbols refer to two or three
dimensional aided symbols that are permanent, manipulable with a
simple motor behavior, tactually discriminable, and highly iconic.
Symbols that can be discriminated on the basis tangible properties
(shape, texture, consistency).
- Real Objects - may be identical, similar to,
or associated with their referents. For example,
- Identical Symbol - "brush your teeth" might be
a toothbrush that is the same color and type as the individual's
- Similar Symbol - toothbrush of a different
color and type
- Associated Symbol - might be a tube of
toothpaste, container of dental floss, wrappers from fast food
- Miniature Objects may be more practical than
real object symbols in some situations buy need to be selected
carefully. May be difficult to recognize by intellectually
- Partial Objects involve those that are large.
For example, top of spray bottle of window cleaner may represent
- Artificial Associated And Textured
- For example, a wooden apple may be attached
to a cafeteria door and a similar apple could be used as the
symbol. Textured symbols may logically or arbitrarily
associated with their referents. A logically associated
textured symbol could be piece of spandex material to symbolize
a bathing suit. Alternatively a square velvet could be selected
to represent a favorite snack.
Representational Symbols include 2
- Mirenda & Locke (1989) - Cognitively
delayed matched color photographs to referents more accurately
than black and white photos
- Sevcik & Romski,(1986) - Cognitively
delayed matched black and white photos to referent more
accurately than line drawings
- Color versus B/W, no data
- Issue of context not clear - Dixon (1981)
found that students with severe disabilities were more able to
associate objects with their color photographs when the
photographic objects were cut out than when they were not.
Reichle (1991) suggested that the context in which a photograph
appears may affect an individual's ability to recognize it, for
example, a photograph of a watering can may become more
recognizable when it appears next to a plant.
- Line Drawings
- widely used system of 1800 simple line drawings. PCS can be
purchased in a variety of formats, including stamps,
books and software.
Exchange System - Single Subject
- Rebus Symbols - A rebus is a picture that
visually or nominally represents a word or a syllable. For
example, a picture of a knot could be used to symbolize either
"know" or "not.
- Picsyms (Dynasyms) is a logical system of
visual-graphic symbols that were developed through work with
young children who were unable to speak. 1800 symbols are
available. New symbols can be created by following the
generative rules that are include with the dictionary of
symbols. Research indicate that Picsyms appear to be similar to
or slightly more difficult than both PCS and rebus symbols and
superior to Bliss.
Ideogram Communication (PIC) Symbols
- consists of 400 white on black symbols designed to reduce
figure-ground discrimination difficulties. Have been used with
severe disabled and autistic individuals.
was developed to function as an auxiliary language for
international written communication. It consists of a 100 basic
that can be used individually or in combination to encode
virtually any message. The original
system consisted of 1400 black and
white symbols with written labels. New Bliss symbols are added
annually by an international panel affiliated with
- Enhanced Blissymbols - A Collection of
Blissymbols are available that have been enhanced by pink line
drawings cues. These enhanced Blissymbols are designed to
remind the beginning user of the concepts that the symbols
- Major strength of Bliss - Principles and
strategies for combining
symbols enable expression of
thoughts not on the communication board. The symbols are
conceptually based and constructed using consistent,
Abstract Symbols Systems
- Yerkish Lexigrams resulted from a primate
research project designed to develop computer based system for
studying language acquisition in chimpanzees. The lexigrams are
composed of 9 geometric forms used singly or in combinations of 2,
3, 4, to form symbols.
- Non SLIP (Non-Speech Language Initiation
Program) symbols were predecessor to Yerkish lexigrams since they
originated in early chimpanzee language work (Premack, 1971).
Symbols are plastic or masonite chips that vary in color, shape
and size and are accompanied on reverse side by printed English
Orthography and orthographic symbols
- Traditional orthography refers to written
characters used to transcribe a particular system (English
alphabet, Chinese characters).
- Orthographic symbols is used to refer to aided
techniques that represent traditional orthography, such as
braille, Morse code, and phonemic symbols.
- Morse code is an international system that
users series of "dits" (dots) and "dahs" (dashes) to represent
letters, punctuation, and numbers. When used in AAC applications,
code is transmitted via microswitches through a device called a
emulator that translates it into orthographic letters and
- Braille is a tactile symbol system for reading
and writing that is used by persons with visual or dual sensory
impairments. Braille characters are formed by combinations of 6
embossed dots arranged within a "cell" of two vertical columns of
three dots each. The characters represent letters, parts of words,
or entire words.
Considerations in selecting
- Openness - Traditional orthography is highly
open because the user can express any item that can be spelled. In
contrast, pictographs have more limited openness, since they do
not provide access to any words or concepts beyond those displayed
on the aid (with the exception of MINSPEAK). Ideographic and
abstract symbols tend to be more open than those that use only
pictures, since it is difficult to represent abstract concepts
through pictures alone. The more open a symbol system is, the more
abstract it is. Symbols must be chosen that will provide the
openness the individual needs but that also are within his
- Intelligibility - The ability of the symbol to
be understood with no prior training. This depends on the output
of the aid and the obviousness of the symbols.
- Electronic Aid - The need for the partner to
understand the symbols depends upon the output produced (printed
- Nonelectronic Aid - The obviousness of the
symbols used is important. If a pictograph is used, the word or
phrase corresponding to it should be printed above it because the
meaning of the symbol may not be obvious to those unfamiliar with
the system. A partner who is unable to read the word printed above
the symbol must understand the specific system being used.
- Strategies - If a pictographic system is used
that allows the user to create new words not displayed, printing
the word corresponding to the symbols may not be of assistance.
For example, in Blissymbols the word talk can be created by
indicating action then mouth. In such a case, the partner would
need to know the strategy.
- Amount of time to learn symbols - Time
available to train the partner to learn symbols must be
considered. If user communicating with unfamiliar partners or
partners with little time available, then symbols easily
intelligible to an untrained person must be used. Thus, with
different partners, symbols from different sources may be used
depending upon the partner's abilities.
Using one symbol set or system versus
- Advantage of using a single set is that if
many individuals in the immediate environment also use it, they
will understand each others symbols and can communicate with each
other. If a specific system is used, the user may be able to
achieve maximum degree of openness by using the strategies and
symbols consistently (rather idiosyncratic) rather than mixing
various sets and systems.
- Disadvantage of using one source is that if a
symbol from a particular set or system is too abstract for the
user or not obvious enough for partners to understand, the
individual may not be able to use it. If the set is limited in
openness, the individual is limited in the ideas that could be
- Mixed - Thus hand-drawn pictographs or those
collected from magazines and photos, prepackaged sets of
pictographic symbols, and symbol systems can be combined. New
symbols can be created incorporating ideas from different sources
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