CATEA.orgassistivetech.netATWiki
Personal tools
Views

Interested in disability history? Check out what happened Today in AT History!

Braille

From ATWiki

Jump to: navigation, search
Braille
Braille

The Braille system is a method that is widely used by blind people to read and write. Braille was devised in 1821 by Louis Braille, a blind Frenchman. Each Braille character or cell is made up of six dot positions, arranged in a rectangle containing two columns of three dots each. A dot may be raised at any of the six positions to form sixty-four (26) possible subsets, including the arrangement in which no dots are raised. For reference purposes, a particular permutation may be described by naming the positions where dots are raised, the positions being universally numbered 1 to 3, from top to bottom, on the left, and 4 to 6, from top to bottom, on the right. For example, dots 1-3-4 would describe a cell with three dots raised, at the top and bottom in the left column and on top of the right column, i.e., the letter m. The lines of horizontal Braille text are separated by a space, much like visible printed text, so that the dots of one line can be differentiated from the Braille text above and below. Punctuation is represented by its own unique set of characters.

The Braille system was based on a method of communication originally developed by Charles Barbier in response to Napoleon's demand for a code that soldiers could use to communicate silently and without light at night called night writing. Barbier's system was too complex for soldiers to learn, and was rejected by the military. In 1821 he visited the National Institute for the Blind in Paris, France, where he met Louis Braille. Braille identified the major failing of the code, which was that the human finger could not encompass the whole symbol without moving, and so could not move rapidly from one symbol to another. His modification was to use a 6 dot cell — the Braille system — which revolutionized written communication for the blind.

Contents

The Braille alphabet

Braille can be seen as the world's first binary encoding scheme for representing the characters]] of a writing system. The system as originally invented by Braie consists of two parts:

  1. A character encoding for mapping characters of the French language to tuples of six bits or dots.
  2. A way of representing six-bit characters as raised dots in a Braille cell.

Today different Braille codes (or code pages) are used to map character sets of different languages to the six bit cells. Different Braille codes are also used for different uses like mathematics and music. However, because the six-dot Braille cell only offers 63 possible combinations (26 - 1 = 63), of which some are omitted because they feel the same (having the same dots pattern in a different position), many Braille characters have different meanings based on their context. Therefore, character mapping is not one-to-one.

In addition to simple encoding, modern Braille transcription uses contractions to increase reading speed. (See: Grade 2 Braille)

Writing Braille

Braille may be produced using a slate and stylus in which each dot is created from the back of the page, writing in mirror image, by hand, or it may be produced on a Braille typewriter or Perkins Brailler, or produced by a Braille embosser attached to a computer. It may also be rendered using a refreshable Braille display.

Braille has been extended to an 8-dot code, particularly for use with Braille embossers and refreshable Braille displays. In 8-dot Braille the additional dots are added at the bottom of the cell, giving a matrix 4 dots high by 2 dots wide. The additional dots are given the numbers 7 (for the lower-left dot) and 8 (for the lower-right dot). Eight-dot Braille has the advantages that the case of an individual letter is directly coded in the cell containing the letter and that all the printable ASCII characters can be represented in a single cell. All 256 (28) possible combination of 8 dots are encoded by the Unicode standard. Braille with six dots is frequently stored as Braille ASCII.

The first ten letters of the alphabet and the digits 1 through 10 are formed using only the top four dots (1, 2, 4, and 5). Adding dot 3 forms the next ten letters, and adding dot 6 forms the last six letters (except w) and the words and, for, of, the, and with. Omitting dot 3 from the letters U-Z and the five word symbols form nine digraphs (ch, gh, sh, th, wh, ed, er, ou, and ow) and the letter w.

Letters and numbers

braille_alphabet
braille_alphabet

Other symbols

braille_numbers
braille_numbers

Note:

* The question mark is represented by dots 2-3-6—the same as the opening quotation mark. Therefore the placement of the dots—before a word or after a word—will determine which symbol it is.

* Opening and closing parentheses are shown with the same symbol. Therefore, the placement context will determine whether the parentheses is opening or closing.


Unicode rendering table

The Unicode standard encodes 8-dot Braille glyphs according to their binary appearance, rather than following the alphabetic order of any particular convention. Unicode defines the "Braille Patterns" character block in the hex codepoint range from 2800 to 28FF.

Literacy

A sighted child who is reading at a basic level should be able to understand common words and answer simple questions about the information presented.[1] They should also have enough fluency to get through the material in a timely manner. Over the course of a child's education, these foundations are built upon in order to teach higher levels of math, science, and comprehension skills.[1] Children that are blind, not only have the educational disadvantage of not being able to see, they also miss out on the very fundamental parts of early and advanced education if not provided with the necessary tools.

Braille literacy statistics

In 1960, 50% of legally blind, school-age children were able to read Braille in the U.S.[2][3] According to the 2007 Annual Report from the American Printing House for the Blind, there are approximately 57,696 legally blind children in the U.S. Out of those school-age children, only 10% use Braille as their primary reading medium.[4]

There are numerous causes for the decline in Braille usage, including school budget constraints, technology advancement, and different philosophical views over how blind children should be educated.[5]

A key turning point for Braille literacy was the passage of the Rehabilitation Act of 1973, an act of Congress that moved thousands of children from specialized schools for the blind into mainstream public schools.[3] Because only a small percentage of public schools could afford to train and hire Braille-qualified teachers, Braille literacy has declined since the law took effect.[3] Braille literacy rates have improved slightly since the bill was passed, in part because of pressure from consumers and advocacy groups that have led 27 states to pass legislation mandating that children who are legally blind be given the opportunity to learn Braille.[5]

In 1998-99 there were approximately 55,200 legally blind children, but only 5,500 of them used Braille as their primary reading medium.[6][7] Early Braille education is crucial to literacy for a visually impaired child. A study conducted in the state of Washington found that people who learned Braille at an early age did just as well, if not better than their sighted peers in several areas, including vocabulary and comprehension. In the preliminary adult study, while evaluating the correlation between adult literacy skills and employment, it was found that 44% of the participants who had learned to read in Braille were unemployed, compared to the 77% unemployment rate of those who had learned to read using print.[8] Currently, among the estimated 85,000 blind adults in the United States, 90% of those who are Braille literate are employed. Among adults who do not know Braille, only 1 in 3 is employed.[3] Statistically, history has proven that Braille reading proficiency provides an essential skill set that allows visually impaired children not only to compete with their sighted peers in a school environment, but also later in life as they enter the workforce.[5]

Though Braille is thought to be the main way blind people read and write, in Britain (for example) out of the reported 2 million visually impaired population, it is estimated that only around 15-20 thousand people use Braille. Younger people are turning to electronic text on computers with screen reader software instead, a more portable communication method that they can also use with their friends. A debate has started on how to make Braille more attractive and for more teachers to be available to teach it.

Braille transcription

Braille Writer
Braille Writer
Braille Pillbox
Braille Pillbox
Braille e-book
Braille e-book

Although it is possible to transcribe Braille by simply substituting the equivalent Braille character for its printed equivalent, such a character-by-character transcription (known as Grade 1 Braille) is used only by beginners.

Braille characters are much larger than their printed equivalents, and the standard 11" by 11.5" (28 cm × 30 cm) page has room for only 25 lines of 43 characters. To reduce space and increase reading speed, virtually all Braille books are transcribed in what is known as Grade 2 Braille, which uses a system of contractions to reduce space and speed the process of reading. As with most human linguistic activities, Grade 2 Braille embodies a complex system of customs, styles, and practices. The Library of Congress's Instruction Manual for Braille Transcribing runs to nearly 200 pages. Braille transcription is skilled work, and Braille transcribers need to pass certification tests.

In English, the system of Grade 2 Braille contractions begins with a set of 23 words which are contracted to single characters. Thus the word but is contracted to the single letter b, can to c, do to d, and so on. Even this simple rule creates issues requiring special cases; for example, d is, specifically, an abbreviation of the verb do; the noun do representing the note of the musical scale is a different word, and must be spelled out.

Portions of words may be contracted, and many rules govern this process. For example, the character with dots 2-3-5 (the letter "f" lowered in the Braille cell) stands for "ff" when used in the middle of a word. At the beginning of a word, this same character stands for the word "to" although the character is written in Braille with no space following it; this contraction was removed in the Unified English Braille Code. At the end of a word, the same character represents an exclamation point.

One problem that can occur when reading Grade 2 Braille is that some contractions are closely similar, even when the words are not. One example compares the contractions "ll", meaning little, and "lr", meaning letter from Barry Hampshire's "Working with Braille".[9] The braille notation for the letter "r" differs only by adding one dot to the letter "l". This causes greater confusion between words that are not as similar in normal print and can hinder the learning process of Grade 2 Braille.

The contraction rules take into account the linguistic structure of the word; thus, contractions are not to be used when their use would alter the usual Braille form of a base word to which a prefix or suffix has been added. And some portions of the transcription rules are not fully codified and rely on the judgment of the transcriber. Thus, when the contraction rules permit the same word in more than one way, preference is given to "the contraction that more nearly approximates correct pronunciation."

Grade 3 Braille is a system that includes many additional contractions, almost a shorthand; it is not used for publication, but is used mostly for individuals for their personal convenience.

Braille reading techniques

Since Braille is one of the few writing systems where tactile perception is used, as opposed to visual perception, a Braille reader must develop new skills. One skill important for Braille readers is the ability to create smooth and even pressures when running one's fingers along the words. There are many different styles and techniques used for the understanding and development of Braille, even though a study by B. F. Holland [10] suggests that there is no specific technique that is superior to any other.

Another study by Lowenfield & Abel [11] shows that Braille could be read "the fastest and best... by students who read using the index fingers of both hands." Another important reading skill emphasized in this study is to finish reading the end of a line with the right hand and to find the beginning of the next line with the left hand simultaneously. One final conclusion drawn by both Lowenfield and Abel is that children have difficulty using both hands independently where the right hand is the dominant hand. But this hand preference does not correlate to other activities.

Braille for other scripts

See main articles: Hebrew braille

There are many extensions of Braille for additional letters with diacritics, such as ç, ô, é.

When Braille is adapted to languages that do not use the Latin alphabet, the blocks are generally assigned to the new alphabet according to how it is transliterated into the Latin alphabet. The alphabetic order of the national script (and therefore the natural order of Latin Braille) is disregarded. Such is the case with Russian, Greek, Hebrew, Arabic, and Chinese. In Greek, for example, gamma is written as Latin g, despite the fact that it has the alphabetic position of c; Hebrew bet, the second letter of the alphabet and cognate with the Latin letter b, is sometimes pronounced /b/ and sometimes /v/, and is written b or v accordingly; Russian ts is written as c, which is the usual letter for /ts/ in those Slavic languages that use the Latin alphabet; and Arabic f is written as f, despite being historically p, and occurring in that part of the Arabic alphabet (between historic o and q). Esperanto letters with circumflexes, ĉ, ĝ, ĥ, ĵ and ŝ, are written as those letters without circumflexes with a filled sixth dot. Therefore the letter ĵ has the same representation as the English w and to write a w in Esperanto, the dot 3 is filled (dots 2-3-4-5-6 are used for w instead of dots 2-4-5-6) The ŭ, used in Esperanto also, is as the u but the first dot is moved to the fourth place.

Greater differences occur in Chinese Braille. In the case of Mandarin Braille, which is based on Zhuyin rather than the Latin Pinyin alphabet, the traditional Latin Braille values are used for initial consonants and the simple vowels. However, on Latin Braille for many of the initial consonants and simple vowels (based on romanizations of a century ago), but the blocks pull double duty, with different values depending on whether they're placed in syllable-initial or syllable-final position. For instance, the block for Latin k represents old-style Cantonese k (g in Yale and other modern romanizations) when initial, but aak when final, while Latin j represents Cantonese initial j but final oei.

At least three adaptations of Braille have completely reassigned the Latin sound values of the blocks: Japanese Braille, Korean Braille, and Tibetan Braille. In Japanese Braille, alphabetic signs for a consonant and vowel are combined into a single syllabic block; inKorean Braille, the consonants have different syllable-initial and syllable-final forms. These modifications made Braille much more compatible with Japanese kana and Korean hangul but meant that the Latin sound values could not be maintained.

Uses

The current series of Canadian banknotes have raised dots on the banknotes that indicate the denomination and can be easily identified by visually impaired people; this 'tactile feature' does not use standard Braille but, instead, a system developed in consultation with blind and visually impaired Canadians after research indicated that not all potential users read Braille.

Mexican bank notes and Indian Rupee notes also have special raised symbols to make them identifiable by the visually impaired.

In India there are instances where the parliament acts have been published in Braille too. For example 'The Right to Information Act'


See also

Braille for other languages

References

  1. 1.0 1.1 http://www.childrenofthecode.org/
  2. http://www.braille.org/papers/jvib0696/vb960329.htm
  3. 3.0 3.1 3.2 3.3 http://www.boston.com/news/local/articles/2008/01/05/a_boost_for_braille/
  4. http://www.afb.org/Section.asp?SectionID=15&DocumentID=4398
  5. 5.0 5.1 5.2 http://www.braille.org/papers/jvib0696/vb960311.htm
  6. http://www.aph.org
  7. http://articles.latimes.com/2001/jun/30/local/me-16960
  8. http://www.nfb.org/Images/nfb/Publications/fr/fr14/fr04se22.htm
  9. Hampshire, Barry. Working with Braille. Paris: Unesco P, 1981.
  10. B.F. Holland, 'Speed and Pressure Factors in Braille Reading', Teachers Forum, Vol. 7, September 1934 p. 13-17
  11. B. Lowenfield and G. L. Abel, Methods of Teaching Braille Reading Efficiency of Children in Lower Senior Classes. Birmingham, Research Centre for the Education of the Visually Handicapped, 1977

Organizations

Libraries

Learning

History

Documents

Legal

Language specific resources

Computer resources