Japanese "Dvorak"

Note, 24 Feb 1999: Click here for more Japanese layout info.

I recently [8 November 1996] exchanged E-mail with Kenichi Asai in Japan, and he gave me some insight into the problem of keyboard ergonomics in Japanese. I tried to find the "T-code" he mentions on the Web, but found the term is used for something else in English! (Some sort of mathematical "Evolution" technique.)

I've gotten some questions about "Dvorak" for other languages, so I thought I'd include Kenichi's brief summary about Japanese "T-Code" here.

>By the way, you might be able to answer a question for me.  A Dr. [Hisao]
>Yamada at the U of Tokyo designed an ergonomic Japanese keyboard layout
>several years ago.  It is supposed to have been "successful," but I don't
>know what that means. Do you know offhand if that keyboard caught on?

Prof. Hisao Yamada is now in Chukyo University in Nagoya (located
between Tokyo and Osaka).  He is reachable by hy_AT_sccs.chukyo-u.ac.jp.
He invented a so-called T-Code for a Japanese input method.  As you
may know, Japanese uses Chinese characters, which count more than a
thousand.  Usually, we input them by their sound.  We input their
pronounciation in alphabet, and computers will show as candidates
several Chinese characters for the pronounciation.  (A lot of Chinise
characters share their sound.) Then, we choose a correct character
among them.

The problem here is that we have to CHOOSE a correct character.  To
choose it, we have to think.  This slows down the input speed of
Japanese text.  We want the input method to be fully mechanical (as in
English).  When inputting text, we think of only its contents, not the
input method.

With this observation, Prof. Yamada invented T-Code.  When using
T-Code, one Chinise character is input by two strokes.  On normal
English keyboards, there are about twenty keys to type for each hand.
By distinguishing the following four cases:
(1) the left hand types both the first stroke and the second stroke.
(2) the left hand types the first stroke and
    the right hand types the second stroke.
(3) the right hand types the first stroke and
    the left hand types the second stroke.
(4) the right hand types both the first stroke and the second stroke.
there are 1600 variations. (4*20*20)  T-Code assigns a Chinise
character to each of them.

This means that we have to remember for each Chinese character which
stroke is assigned among these 1600 combinations.  At first sight,
this seems ridiculous.  How can we remember that amount of stuff!
But the actual experiment says that we can remember them after about a
month of training, and then, we can type Japanese text without
interupting our thinking, without seeing display, and completely

In my former lab, a guy actually uses T-Code.  He can now type most
Chinise characters that occur often.  (By the way, he uses Dvorak when
he inputs alphabets.)  He can probably type Japanese text without
seeing the display at all.  It seems that it's not so unrealistic to use
T-Code.  I?  No, I don't use T-Code, although I think it is an
interesting choice.  Is it popular?  No.  Most people don't want to
remember 1600 combinations.

Hope it helps you some.


Kenichi Asai

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Last update: 8 November 1996
Original page established: 8 November 1996
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