Measuring linguistics of the wokototen chart made inductively by deciphering kunten materials

Overview of wokototen

Wokototen markings are often found in kunten documents from the Heian and Kamakura periods, where they are used to indicate features such as grammatical particles, auxiliary verbs, and conjugated endings by means of variously shaped symbols such as dots (・), lines ( │ ), and hooks (└ ). These symbols can be placed at the four corners, inside, or around the strokes of a Chinese character, and their readings differ depending on their position and shape. For example, a dot to the upper right of a kanji has a different meaning than a line in the same position, or a dot to the lower right of the character. To uniquely identify the meaning of a wokototen markings, we need to know both its position and its shape.

There are various types of wokototen associated with different eras and different schools. For example, in one school, a dot at the upper right corner of a Chinese character is read as wo, but in another school, it is read as koto.

Wokototen charts and the study of kunten

The decipherment and classification of wokototen has been the subject of several previous studies by researchers including Yoshinori Yoshizawa,^5–7 Norio Nakata,⁸ Heiji Otsubo,⁹ Hiroshi Tsukishima,^4,10 Yoshinori Kobayashi,^11,12 and Masaji Kasuga.¹³ In particular, Norio Nakata⁸ compiled a set of 26 wokototen charts as materials for deciphering kunten materials.

Even today, researchers specializing in wokototen are working to decipher kunten materials and study their historical background. Their general research method involves visually deciphering the wokototen and kana annotations in kunten materials to create Japanese transcriptions from which the contents of the materials can be understood. As a by-product of this process, a wokototen chart is generated as a key to the markings used in the source material. A wokototen chart not only summarizes the wokototen markings in the actual kunten materials, but also includes information on how the researchers understood these materials.

As shown in Figure 1, a wokototen chart indicates the reading of each marking according to its shape and position in a square frame (called a tsubo) corresponding to the location of a Chinese character. A wokototen chart typically consists of multiple tsubo, with each tsubo containing multiple wokototen. A collection of these wokototen charts is called a tenzushū (点図集).

Figure 1. Example of a wokototen chart for Kobunshōsho (古文尚書), an important cultural property held at the Toyo Bunko Museum in Tokyo made by Teiji Kosukegawa.

Wokototen charts can be classified into two types according to the process by which they were created. One is a comprehensive chart, which is a collection of the wokototen markings used by each school. The other is an inductive chart, which is a collection of the wokototen markings used in a particular body of kunten material. The measurements in this study were made using the latter type of chart. For this paper, we performed basic measurements on 199 types of point charts contained in actual kunten materials as summarized by Hiroshi Tsukishima.⁴ By way of comparison, we also present the results of measurements made using the former type of point chart as described by Tomoaki Tsutsumi.¹

Digitization of wokototen chart data

The data used in this study was based on wokototen charts data created from kunten materials created by Hiroshi Tsukishima, which were registered as of June 2022 in the Wokototen charts Database provided by the National Institute for Japanese Language and Linguistics (NINJAL). Further information on the database can be found on the NINJAL website and in reference [3].

As mentioned above, wokototen markings are used to annotate Chinese characters. The meaning of each marking is determined by its position, shape, and reading. In the data of NINJAL, the 'reading' of the wokototen has been entered in Japanese text. The ‘shape’ of the wokototen has been entered by replacing it with the similar character in Unicode. The 124 characters substituted in this database is shown in Table 1. The position of a wokototen is represented using a 7×7 square grid of cells with its origin at the center of a tsubo and the upper left and lower right corners at the coordinates (−3, −3) and (3, 3). Since wokototen markings are sometimes slightly separate from the kanji character, the center 5×5 square corresponds to the area occupied by the character, and coordinates in this region correspond to markings that overlap with the character. The outermost cells are used for positions that are separate from the kanji character. This digitization method of the readings, positions and shapes of the wokototen are described in detail in reference [1].

Table 1. List of shapes used for digitisation.

Shape
・	┼	七	/	丁	⠑	ア	ᓓ	カ	ހ	┼又は┤
｜	：	レ	╰	〝	ム	4	॥	マ	い	ဂ
—	〢	ナ	—↑	ク	リ	丿	⨽	∧	下	凵
＼	〇	ノ	ᄓ	⠔	┤	つ	…	٦	ᨀ	⍭
└	乙	◠	⧷	ﾌ	∴	∠	y	⎞	山	N
／	├	ル	イ	ス	コ	⍀	匚	◠↓	⦧	亽
┐	＝	┴	×	ヒ	＞	┌	上	৲	-	冖↓
フ	┬	⧹	⊂	—↓	へ	ヌ	〃	C	丶	ち
人	⊃	∨	⌵	┘	口	∪	⦣	寸	牛	ケ人よこ
‥	◡	ソ	<	⦦	╲	〵	⁐	ᓗ↑	ᚇ	く
⌰	∅	⎱	𝙻	ﬧ	匕	ヤ	う	⎵	∵	又ハ┤
ヘ	～

This method of expressing the position of the Kunten in coordinates has also been used in Korean studies of gugyeol,^14–18 where a coordinate system of 5×5 squares is defined around each character. These methods of the Korean studies and the current one has the same concept but are not data compatible.

Basic measurements for wokototen charts

In this study, we performed measurements on 199 types of point charts (contained in actual kunten materials as summarized by Hiroshi Tsukishima⁴), relating to the reading, position, and shape of wokototen. The programme written in C# was used for the measurements.¹⁹ Excel 365 and Visual Studio Code (version 1.67) were used to view and compare the data from the database with the reference [4] and to correct the data. VisualStudio Community (version 17) was used to create the programme.

This program reads comma-delimited data, one per line, on the wokototen to be measured. It is a simple program that outputs the count of “reading,” “position,” and “shape” of the wokototen. A line of read data should be produced in the following format.

Material Title,Tsubo No,Reading,Sharp,Position of X, Position of Y

Ex. 華厳経探玄記 一巻,1,レ,・,-3,-3

We created this form of data by comparing data taken from the Wokototenzu database with the previous research.⁴ In some cases, there were multiple readings given for a single symbol in the wokototen chart. Examples are shown in the 'カ/ナ' in the top left-hand corner (-2, -2) of the fifth tsubo in Figure 1. In this case, we have divided the symbol into two separate totals. The one of wokototen of the shape ‘L’ reading ‘カ’ and the other of wokototen of the shape 'L' reading 'ナ. In the data created by adding these processes, the total number of target wokototen was 6411.

Results for reading of wokototen

The readings of wokototen, such as “wo” and “koto,” were examined to determine how many were found in the target wokototen chart. As a result, there were 303 types of readings. Next, the number of these 303 types of readings on the wokototen chart were measured, and the top 10 types are shown in Table 2. This does not include 885 points for which no reading was noted.

Results for shapes of wokototen

We examined the shapes of wokototen markings such as ・ and │ to determine how many of each there were in the target wokototen chart. As a result, we found 124 different shapes. We then counted the occurrences of each of these shapes in the wokototen chart, and the top 10 shapes are shown in Table 3. Since the wokototen charts used in this study were hand-drawn, there were several shapes that were partially similar but with slight differences. In such cases, we counted the shapes as being of a single type. For example, the shapes 人 and 入 were grouped together as 人 and counted as the same shape.

Next, we examined the shapes used to indicate the three most frequent readings, which were “te”, “ni”, and “wo”. As shown in Table 4, we found that these readings were represented by seven shapes: ・, \, /, |, ─, ◡, and :. The ・ shape was the most common.

Result for positions of wokototen

The results of measuring the locations of wokototen markings are shown in Table 5 and are depicted graphically in Figure 2. In Table 5, the area with the red background shows the position of the square cells representing the location of the kanji character.

Figure 2. Number of wokototen by location (graph).

Reading

As Table 2 shows, there are many particles and auxiliary verbs such as “te”, “ni”, “wo”, and “ha”. The most common reading was “te”, which had more appearances than the number of wokototen charts (199) because it sometimes appeared more than once in the same chart, and because there were only eight charts in which this reading was not mentioned. These were charts with an extremely small number of wokototen points. One example is Scroll 1 of the Biography of Yang Xiong Zhuan (漢書楊雄傳; yellow markings, 5th level), which has only one wokototen marking, Scroll 3 of the Mohe Zhiguan (魔訶止觀; green markings), which has eight, and Scroll 1 of Huiguo Heshang Zhi Bei (惠果和上之碑文; black markings), which has two. In cases where the markings appear in different colors, such as red/vermillion (shuten), black (bokuten), and white (hakuten), the symbol “te” was marked in a different color. The same is true for “wo” and “ni”, which explains why “te”, “wo”, and “ni” in particular are found in almost all wokototen charts.

A comparison with the results of a survey¹ of 26 major wokototen charts compiled by Nakata⁸ and Tsukishima⁴ for each school shows that there are differences in the types of readings that occur frequently. The most common readings in the major wokototen charts are “su”, “naru”, “nari”, and “tari”, but these occur less frequently in wokototen charts based on kunten materials. Of these readings, the most common was “su” with 166 occurrences, followed by “nari” with 149. The other readings “tari” and “naru” were the 22nd and 24th most frequent, with 80 and 77 occurrences, respectively.

Shapes

Table 3 shows that the overwhelming majority of wokototen markings are dots (・). There were six wokototen chart that did not contain dots. These were charts containing almost no wokototen, as in the Biography of Yang Xiong Zhuan, and charts where the \ shape was used for the first tsubo instead of a dot, as in Scroll 1 of Tōdaiji Fujumonkō (東大寺諷誦文稿) and Scroll 8 of Myōhō Rengekyō (妙法蓮華経; the Lotus Sutra).

Including the dot marking (・), which appeared most frequently, the wokototen shapes ・, |, ─, and \ that appeared more than 500 times are shapes that can be written with a single stroke. More complex shapes appeared less often, and the same trend was observed in the measurement results of the 26 main wokototen charts.

The results in Table 4 also show that readings with the highest number of appearances are often denoted by a single dot. Although other shapes are sometimes used, it is safe to say that these readings are almost always denoted by a dot in all schools. This is thought to be because particles that are important in reading Chinese texts as Japanese are often expressed in the simplest way, which means using a single dot, because of the large number of times they are added. In some cases, “wo” is represented using the ◡ shape, and these were the wokototen charts belonging to the fourth group in the classification according to Tsukishima.⁴

Position

From Table 5, it can be seen that wokototen are often drawn at the four corners and the center of a character. The most common location was the lower right corner (2, 2), where 709 wokototen were found. In the four corners of characters, where wokototen markings are often placed, markings were more commonly found in the lower corners in the vertical direction, and on the right side in the horizontal direction.

Next, we examined the wokototen markings placed around the outside of the characters. More markings were found on the right side than on the left side. For example, there were 129 markings in the upper right external position (3, −3), but only one in the upper left external position (−3, −3). The most common positions of wokototen markings around the outside of a character were the top, middle and bottom on the outer right side, with the largest number (169) appearing in the middle at coordinates (3, 0). These results show that wokototen, like furigana, tend to be written to the right side of each character.

The above trends suggested by our measurements differ from the results obtained from the 26 main wokototen charts, where there was no difference in the placement of markings between the left, right, upper and lower positions. In addition, measurements of the 26 main wokototen charts showed that few of these markings are placed outside the characters, while in the actual materials it can be seen that many wokototen markings are placed to the right of each character. These differences may represent a trend caused by the actual addition of markings to kunten materials.