A case for DVORAK layout

Peter norvig recently published some word frequency and letter frequencies.

See original here:

I did a quick overview and at the look at letter frequencies,
I had to immediately interpret it as good for DVORAK.
Anyway,here’s the table for top 50% of letters(13)(ordered by frequency of occurence)

Letter Count PERCENT
E 445.2 12.49%
T 330.5 9.28%
A 286.5 8.04%
O 272.3 7.64%
I 269.7 7.57%
N 257.8 7.23%
S 232.1 6.51%
R 223.8 6.28%
H 180.1 5.05%
L 145.0 4.07%
D 136.0 3.82%
C 119.2 3.34%
U 97.3 2.73%

Now these 13 letters account for a total frequency of 84.05%.
That’s a 0.84 probability the letter you type is one of these.

Let’s see how many of these are in the home row.
For Qwerty:
Total = 23.41%

Or there’s a probability of 0.2341 that you’ll hit the key,
without moving from the home row.

For Dvorak(US-Right handed layout):
E,T,A,O,I, N,S,H,D,U
Total = 70.36
That’s a probability of 0.7036 that you’ll hit the key,
without moving from the home row.

Now, this is just a peek.
Infact one can argue that key sequences have a bigger impact on typing speed,stamina, and accuracy.
For those, we can take a look at Bigram,Trigram,..N-gram sequences and frequencies.
Only in those case the analysis gets a little more complicated.
i.e: is it better to have 2-letter sequences on one hand or across two hands?,
is it better to have contiguous sequences(2,3,4…) across rows or in the same row?

Intuitively, some of these questions seem trivially answerable.
like: 2-letter sequences/bigrams are better if they are distributed across hands.
Less no. of rows for an N-gram the better etc..

But a little dose of skepticism is in order. Anyway, will take a shot at that advanced analytics later.

Another relevant link can be seen here.
It takes as input any text you care to copy,paste(i recommend your most typical typing session)
and plots a heat map of the keys, for different layout.