Abstract: Braille, the well known information medium for persons with blindness, entails a difficult-to-solve problem, namely, that the human tactile system can hardly read braille at a reasonable rate. Enhancement of the recognition of braille characters is known to be effective in increasing the rate of reading braille. On the basis of experimental results obtained by the authors, showing that there is a qualitative difference between fast readers and slow readers in their braille character recognition, a new program was developed that teaches persons with blindness the method that fast readers use to recognize braille characters, in order to increase their reading rate. The teaching program consists of a list of braille characters organized in terms of dot position. Application of the program to two contrasting cases suggested that: (1) the fast readers' method of recognition is necessary for fast reading. and (2) the new program can be effective in teaching the fast readers' recognition strategy.
Braille is well known as the alphabet or information medium of persons with blindness. Its superiority over alternative, such as embossed Roman letters or Japanese syllables, was proved long ago (Ohkawara, 1937). However, braille has a number of shortcomings. First, it takes much more space than print does. A small printed dictionary, translated into braille, requires a whole book shelf. Second, communication in written words with persons with sight is not instantaneous, that is, a special translation is needed between braille and print, which requires special knowledge and time. It is directly reflected in the difficulties of braille publishing. Third, Japanese braille does not deal with Chinese characters (Kenji information) conventionally. Lastly, braille is difficult to read. Even the fastest reader with blindness can read only 600 Japanese braille cells per minute, or 125 words per minute (wpm). Average readers read about 60 wpm. Thus, the rate of reading braille is one-fourth to one-third of the rate of reading print visually.
Recent developments in the technology of information processing and electronics have been overcoming the first three of these shortcomings. Soft braille, or paper less braille, enables a reduction in the amount of space needed, and provides direct access by persons with blindness to the same information stored electronically by sighted people (Oda, Koyanagi, & Nagata, 1985). Computer translation between braille and print is now available for popular microcomputers. Chinese characters (Kanji) have begun to be coded in braille. Eventually, one problem will remain, namely, the slow rate of reading braille, for it is a problem of the human tactile sense, difficult to solve by means of technological development. This article describes a promising attempt to solve this problem. (Abandonment of braille is another choice, but, other than braille, persons with blindness have no successful medium with which they can both read and write. Even people with blindness who use computers need braille to keep track of their thoughts. Braille might be their first-hand medium of thought. A paper less braille device which is a note-taking device with braille input and speech output would be a compromise solution to this problem. However, such a device is outside the scope of this manuscript.)
The attempts that have been made to increase the rate of reading braille can be classified into three categories. In the first category are attempts to encourage slow readers to acquire the reading habits of fast readers. Fast readers of braille are known to scan braille text smoothly at a constant speed without rubbing the characters and with relatively light pressure (Burklen, 1932; Kusajima, 1968; Lowenfeld, Abel, & Haltlen, 1969). No scientific evaluation has been made of this approarch (Foulke, 1984). The second category includes attempts to speed up reading by external pacing. In a typical method, braille reading material embossed on a continuous tape is moved underneath the readers' stationary fingers, and the rate of movement of the tape is increased gradually. Researchers have disagreed about the effectiveness of this method. From a carefully controlled experiment, Nolan and Kederis (1969) concluded that the reported effectiveness was questionable and likely to be an artifact of motivation, which had not been controlled. The third method is to strengthen braille character recognition. Nolan and Kederis (1969) found that a half hour of training on braille character recognition for 18 consecutive school days could significantly improve both braille recognition and braille reading rate in school children with blindness, independent of their motivation. This braille recognition training is the only scientifically proved method for increasing the rate of reading braille.
Iwatsubo (1979) suggested that fast readers recognize braille characters differently from slow readers. The school children with blindness whom Nolan and Kederis (1969) trained simply tried to recognize random sequences of braille characters as quickly and correctly as possible. Therefore, there is a possibility that if the method that fast readers use to recognize braille could be taught, reading rates could be increased more effectively.
Two experiments were conducted to analyze the difference in braille character recognition between skilled braille readers and slow readers (Kizuka, Oda, & Fujii, 1985; Kizuka, Oda, & Shimura, 1985). An attempt was also made to discover factors that might affect braille character recognition.
Thirty subjects, 19 females and 11 males, participated in the experiments. Most of the subjects were students at the Sapporo School for the Blind. Information was obtained from all individuals on their chronological age (median: 15 years), the age at which they lost their sight, the length of their experience with braille, their hand preference in reading braille, and the two-point discrimination threshold of their reading (index) finger. With one exception, the subjects had lost their sight at birth or in the early years of their life (median: 0 years old). Most of the subjects were totally blind; only three of the thirty had 0.01 of residual acuity in either eye. All of them read and wrote braille every day. The braille reading rate was measured for each subject to differentiate fast and slow readers. The reading material used was taken from a second-grade elementary school textbook.
In the first experiment, a list of randomly ordered braille characters was presented, to measure the subjects' recognition rate and accuracy. In the second experiment, which used a different set of randomly ordered braille characters, the subjects were asked to report verbally on how they recognized braille characters. The subjects scanned a given character in the same way as they usually did, and then, after scanning, described what they touched in terms of both the recognition of the physical appearance of the braille character and the Japanese syllable for which the braille character stood.
On the average, the subjects had been reading braille for 9.8 years and could recognize 117.6 cells per minute. Their average reading rate was 285.9 cells per minute, or 57.2 words per minute. These results are consistent with what is known about the rate of reading braille. The accuracy measure was not informative, because few errors were recorded. A correlational analysis showed a high correlation (r=0.79) between recognition rate and the rate of reading braille (see Fig. 1). It was also found that the longer the subjects had used braille, the faster their recognition (r=0.60) and reading (r=0.47) rates were. Because most of the subjects had lost their sight in childhood, their chronological age was closely related to the length of their experience with braille (r=0.84). There was a moderate correlation of chronological age with recognition (r=0.52) and reading rate (r=0.39). The residual vision of the subjects had a low but significant negative correlation with recognition and reading. This means that a reader who is totally blind might read braille faster than a reader who is partially sighted. Hand preference, the two-point discrimination measure, and the age of losing sight were not significantly related to recognition or reading rate.
It was found that there was a difference in how readers with blindness recognize braille characters. Since the subjects' verbal descriptions of their recognition methods were diverse, some classification was necessary. The classification employed had seven categories, as listed in Table 1: in category A is recognition only as separate dots; category B consists of descriptions of horizontal bars and separate dots; category C, of vertical bars and separate dots; category D can have angles and separate dots; category E requires diagonal bars and can have additional dots; category F consists of a rectangle and additional dots; category G is similar to F, but instead of a rectangle, it has a triangle or a quadrangle with diagonal lines (see Table 1).
According to this classification, the thirty subjects recognized 63 single-cell braille characters in the way shown in Table 2. The subjects responded to braille characters of the same geometrical structure, such as "i" and "e", in the same way. In Table 2, those characters are grouped and represented by a typical character.
It is possible to divide braille characters into two groups. For one of these groups, the subjects' responses agreed well and were in large part determined by the dot configuration of the braille cells. For instance, the braille character for "a", a single dot, cannot have alternative choices in braille characters for "i", "e", "o" and "w", subjects used a variety of recognition methods. Mann-Whitney's U test revealed that slow readers and fast readers recognized this second group of characters differently. Those who recognized the braille characters for "i", "e", and "o" by the A-category method, and those who recognized them with the E category method, had significantly different reading rates (see Table 3): the faster readers were more likely to use the A-category method. Likewise, they were likely to recognize "w" using the C-category method, while the slow readers tended to recognize it by the G-category method. This result is consistent with Iwatsubo's (1979) research. Despite the fact that no significant difference was found in reading rate, those who recognized the braille character for "w" according to the D-category method were significantly faster than those who used the G-category method. Those who had read braille longer used the B-, C-, and D-category methods significantly more frequently than the E- or G-category methods. Taking into account that reading rate has a high correlation with recognition rate and the length of experience with reading braille, the B-, C-, and D-category recognition methods are superior to the E- and G-category methods with respect to reading rate.
The difference between these two groups of recognition methods is generally the connected distance between dots within a braille character, or the orientation of the connection line between these dots. In the B-, C-, and D-category recognition methods, no dots more than 2.2 mm apart-which is the smallest distance between adjacent dots-are connected. In other words, no diagonal connections are made. In the recognition methods of categories E and G, dots 3.1 mm or more apart are connected, and diagonal connections are made. The fast readers' recognition seems rather more dot-conscious, while the slower readers' recognition is more oriented global shape. Although is was suspected that the two-point discrimination threshold of the subjects' finger tips contributed to this difference, there was no statistical support for this relationship. Therefore, independent of tactile sensitivity, persons with blindness should be encouraged to become sensitive to dot position, instead of to the global shape of braille characters.
The conventional program for teaching braille is as follows. Braille characters are taught one by one. After the characters are learned, two-character words are introduced. As readers gain confidence in reading short words, longer words and short sentences are introduced gradually. Once short texts have been introduced, the teaching program finishes with an introduction to fast readers' reading habits, for example, using both hands. From then on, readers are simply encouraged to read more and faster.
In the conventional methods, braille characters are introduced in one or the other of the following ways. A Japanese braille character consists of two parts, the vowel part represented by the first, second, and fourth dots, and the consonant part coded by the other three dots, just as the Japanese "alphabet" or syllabary (Kana) consists of consonant-vowel syllables. In the first way, braille characters are taught in an analytical way, by explaining how vowels and consonants are coded. The order in which braille characters are taught also corresponds to the Japanese syllabary. In the other method of introducing braille characters, teachers group the characters on the basis of the similarity of their shape in braille. Either easily distinguishable braille characters, or characters of the same geometrical structure, are taught at one time, in order to make recognition easier. Braille characters are easy to understand and memorize with the former method, especially when the preson with blindness knows the Japanese syllabary. Although this method is simple and easy, it is not as successful in practice as it may seem to be at first glance. The consonant and-vowel analysis on which coding rule of braille characters is based is not simple to understand for young children, and even for those who have understood the rule, the difficulty in tactile recognition of braille characters prevents reading. The latter method is concerned with the tactile recognition of braille character shapes. However, as described above, the recognition of the shape of braille characters does not correlate with competence in reading. It is necessary to assume that there is a process suitable for braille reading that is different from that for general tactile pattern recognition, whose goal is to pick up information about geometrical shapes. The braille teaching program should be reconsidered.
A new braille teaching program was developed by the authors, based on the experimental findings described above. Unlike conventional methods, in the new program, words and sentences are introduced simultaneously with braille characters. Persons with blindness are encouraged from the beginning of the program to read with both hands, and to imitate fast reading habits. More-over, the new program has a specific list of which lessons are the most important. Braille characters are classified not by their global-shape similarity, nor by their in the syllabary, but by their dot configuration. Braille characters of the same dot configuration constitute a lesson (see Table 4; some lessons specific to the Japanese braille system are excluded from Table 4 for the sake of simplicity of exposition). For example, braille characters that include the fourth dot are featured in the second lesson. In each lesson, the characters selected for that lesson are exclusively introduced, and persons with blindness are asked to identify them by scanning over them smoothly. Vertically bisected braille characters are also introduced with spaces between them. Presons with blindness are asked to learn the mental skill of integrating the bisected half-characters into ordinary braille characters. For instance, a braille character constituted of the first, second, and third dots is presented, and then, following a space, a braille character constituted of the first (fourth) dot is presented. The subjects are asked to integrate them into the braille character for "p" mentally, by assuming the former braille character to be the left half, and the latter to be the right half of a single braille character. Once the subjects' performance of character identification reaches a certain criterion, words and short sentences are introduced in the same lesson. The words and the sentences consist of the selected characters exclusively. In some cases, characters introduced in ore ceding lessons are used in later lessons to make up words and sentences. Unlike the method used initially in teaching characters, there is no comparable task involving the integration of bisected characters in the part of the training program in which words and sentences are taught. The lessons are designed so that one lesson can be completed within a day.
The new program has been applied to two cases. One case was a boy who had become blind in an accident. He knew braille characters, but could not read at a practical speed. The other was a girl who was congenitally blind; she could read braille at a practical rate, but an attempt was made to increase her rate. The former case kerned slowly, but can be said to be successful in terms of recognition of braille characters. The latter case could not increase her reading rate nor improve her recognition of braille characters.
In the former case (Kizuka, Oda, & Oshiro, 1986), the boy had had cataracts in both eyes at birth; he had no additional disability. The clouded lenses of his eyes were removed surgically when he was very young (one at 18 months of age, and the other a year later). These operations saved his eyesight, and he was enrolled a special class for children with low vision in a regular elementary school. When he was in the third grade, for some reason he lost the sight in his right eye totally. He continued as a pupil in the same special class, using the residual vision (acuity around 0.1) in his left eye. However, a sudden detachment of the retina and successive hemorrhage in the vitreous body of his left eye made him legally blind (he could only see hand movements). No further surgical operation could improve his vision, and he was transferred to a school for the blind. It was one year after he started learning in that school that he visited the Education Guidance Clinic of the National Institute of Special Education. When he started the new teaching program described above, he already knew braille to a certain extent. In practice, he could use the perkins Brailler to type the braille syllabary, and could read braille very slowly at the rate of one line a minute. The way he read braille was typical of slow readers, that is, rubbing the characters one by one vertically, sometimes destroying the braille dots with high pressure. Overprotection and his family's postponed acceptance of his blindness seemed to have deprived him greatly of necessary experiences. In other words, he was astonishingly behind his peers in terms of cognitive skills, knowledge, body movements,and vocabulary, although it was clear that his intelligence was intact.
His training was conducted mostly on a weekly basis. Successive lessons were introduced one by one, with review and exercise lessons intervening roughly once every two lessons, the whole program took about half a year to complete. His reading rate in each lesson slowly increased (see Fig. 2). Frequently his attention had to be drawn to his character-rubbing reading habit in order to change it into efficient and smooth scanning. He needed many explanations about the meaning of the words and sentences in the lessons. A typical lesson took more than two hours, for this reason.
His reading rate increased from 6.6 wpm at the beginning, to 15.6 wpm at the end. This means that his reading rate doubled. The resulting rate of reading exceeded the threshold (15 to 20 wpm; Goldish & Taylor, 1974) at which reading could just become practical. His increased reading rate correlated with an increase in recognition speed (from 22 to 48 characters per minute).
As the authors had expected, his recognition of characters changed in the direction that is desirable for fast reading. Recognition using the A-, B-, and D-category methods increased, while those using the E- and G-category methods decreased, as shown in Table 5, even though he was not asked explicitly to recognize the characters using these methods. Rather, a sequence of lists of braille characters organized in terms of dot configuration was simply presented to the subject systematically, and he was encouraged to acquire a smooth scanning habit. In short, the fast readers' method of character recognition was learned as a result of the program.
It is interesting to note that although the subject learned the fast readers' method of recognition, he still read relatively slowly. After the completion of the program, he could start reading braille materials in the classroom. His reading rate began to increase, which provided him with more exposure to braille. The authors were told that a year later, he was able to read braille at around 60 wpm. This result might mean that using the fast readers' recognition method is a necessary but not a sufficient condition for fast reading.
The second case will be described here very briefly. A girl who was born blind was referred to the Educational Guidance Clinic of the National Institute of Special Education when she was in nursery school. She had already learned braille and could read about 20 wpm at that time. In each lesson, she showed great difficulty in integrating bisected characters, although she could read the words and sentences easily. She seemed to resist accepting half-cell characters as bisected halves of braille characters. It was obvious to the authors that she could not learn what was intended and could not apply it when reading. She simply went through all the tasks by using what she already knew. She reached the criteria by memorizing the materials in the identification tasks. Consequently, she showed no improvement either in reading rate or in character recognition. Her method of recognizing braille characters remained oriented toward the global shape of the characters, that is, mostly in the E- and G-category methods. After the completion of the program, she received totally different lessons in braille reading from a teacher with blindness. The teacher reported that the girl showed little improvement in her braille reading. Some factors with which she managed to read 20 wpm may be qualitatively different from those with which she might be able to read faster. The recognition of braille characters should be one of those factors.
Braille character recognition is a key factor in increasing reading rate. The experiments reported in the present manuscript showed that fast readers differ qualitatively from slow readers in the recognition of braille characters. Fast readers are more aware of the position of the dots in the braille characters, while slow readers' recognition is global-shape oriented. The present manuscript suggests how the recognition of braille characters should be altered in order to increase the rate at which they can be read.
Based on these findings, a new braille teaching program was developed, consisting of lists of braille characters organized in terms of the position of the dots. The application of this program to an adventitiously blind boy resulted in acquiring the fast readers' method of recognizing braille, which facilitated his reading afterwards. Conversely, the program produced no success with a child with congenital blindness who thus remained at her slow rate of reading. Despite the limited number of cases, these two contrasting applications suggest the following points. The new program can be effective in teaching the method of recognition used by fast readers. although it is not always successful. The fast readers' method of recognizing braille characters may be one of the necessary requirements for fast reading. Even those who could read with practical speed could not transfer to even more efficient reading without the fast readers' recognition strategy. Once readers have acquired the fast readers' recognition strategy, their braille reading will improve simply as a result of their experience. The research findings described above encourage the authors to continue applying and revising the training program.
This research was supported by government grants 57115001 and 58107001 from the Ministry of Education, Science, and Culture. We are grateful to Mr.Kenzo Fujii, who was teaching at the Sapporo School for the Blind and provided much help in the experiments.
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出典：National Institute of Special Education Bulletin 、Vol.3、pp.49-56、1989年.