Dvorak improved
Hear, hear Mr. Apple and Mr. Microsoft: the U and I on the Dvorak keyboard layout should be switched, it's a big mistake!
Since around two years I am typing with the Dvorak-Dealey keyboard layout instead of the standard QWERTY layout. I am glad I switched. The only reason not to switch is not wanting to invest the effort to learn it; as most systems today support Dvorak (windows mobile 6 doesn't). When using a computer in an internet cafe or at a friends place I download and start my personal key re-mapper, a autohotkey script, so I can type in my adapted layout.
Typing itself is not that much faster as you formulate paragraphs slower then you can type, but it is way more comfortable. For me that is important in stress situations - which I try to avoid - which can aggrevate a returning muscle pain in my wrists as I suffered RSI a while ago.
It is possible to calculate and evolve a slightly more optimal layout with a keyboard layout evolver like kiwi, but for me it wouldn't be worth the effort to find it and re-learn it. I found one glaring issue with the Dvorak layout: the placement of the U and the I, they should be switched as [Michael Capewell] (http://www.geocities.com/smozoma/projects/keyboard/layout_capewell-dvorak.htm) noted. The reason is that the frequency of the letter U in the English and Dutch language is much less compared to the letter I frequency, also the frequency of the Dvorak two letter combinations (digrams) you can make with the letters on the left-hand with the U are also less then with the I.
This means you have to move your left index finger more and strain your left hand extra. When typing for example chapter 1 of Dreaming Void the letter i occurs 429 times compared to the 211 u's. The number of U digrams in the text typed with the left hand is 150 and 232 with the left hand. The number of I digrams typed with the left hand is 98 and with the right hand 688. It's obvious the I is best placed under the left index finger instead.
Now the distance traveled with your fingers is 218 meters when typing in Qwerty, 118 meters in Dvorak and 111 in Dvorak with the U and I interchanged. So it's around 7% more efficient in that way.
By counting the involved letter and bigram frequency one can measure the efficiency of swapping the keys. One can weigh the higher I frequency compared to the U frequency with the OU frequency compared to the OI frequency and come up with this approximation to measure the reduction of finger movement when switching the U and the I. Technically one should compare all the possible U/I digrams, but this would be complex and one would also have to factor in the cost of digram finger movement which differs for each non vowel-vowel left-hand digram. Fortunately most of the vowel-vowel digrams are in the top digram list for the left dvarok hand and comprise around 75% of the total left-hand letter digrams. So one could leave them out to get an estimate of the left-hand extra movement.
The measure is: (freq u + u-vowel left hand digrams) / (i + i-vowel digrams left hand)
| title | measure | improvement |
|---|---|---|
| simple english bible | (44997+30877)/(57920+26312) | 0.90 |
| alice in wonderland | (2042+1334)/(2587+1181) | 0.90 |
| some science text | (99+56)/(111+74) | 0.84 |
| dutch text | (56+37)/(62+56) | 0.79 |
In my native language Dutch the OU digram doesn't occur as frequently making the benefit of switching the U and I even greater. I haven't tested french but I suspect the OU digram frequency is similar to that of english.
Here is the count of left-hand letter digrams for the dvorak layout in the simple english bible:
| frequency | digram |
|---|---|
| 1649 | ou |
| 741 | ai |
| 222 | io |
| 219 | qu |
| 215 | up |
| 212 | ki |
| 206 | ie |
| 169 | ue |
| 134 | pi |
| 126 | oi |
| 109 | ei |
| 102 | ju |
| 98 | ik |
| 90 | ui |
| 83 | pu |
| 81 | au |
| 52 | yi |
| 45 | ia |
| 23 | xi |
| 23 | ua |
| 23 | ip |
| 12 | iu |
| 10 | ix |
| 3 | uo |
| 1 | ku |
| 1 | eu |
And these are the left-hand vowel vowel digrams:
| freq | digram |
|---|---|
| 1649 | ou |
| 741 | ai |
| 222 | io |
| 206 | ie |
| 169 | ue |
| 126 | oi |
| 109 | ei |
| 90 | ui |
| 81 | au |
| 45 | ia |
| 23 | ua |
| 12 | iu |
| 3 | uo |
| 1 | eu |
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