Some of you may be familiar with my carpalx project
which attempts to construct a model of typing effort, evaluate existing layouts using the model and try to find more effortless alternatives.
I've done quite a bit of revamping of the model and analysis, and wanted to therefore drop a note here to invite you over to the project pages and make a few comments about my recent experiences in evaluating and improving layouts. The recent release also includes PKL layouts.
As most of you expect, Colemak is a great layout with arguably the best statistics out of the popular alternatives.
http://mkweb.bcgsc.ca/carpalx/?popular_alternatives
My model of typing effort actually had a hard time on creating a layout that improved on Colemak on all three types of effort: finger distance, finger and row penalty and stroke path. Initially, I wanted to generate a justifiable model of typing effort and then, having created one, wanted to know what kind of layouts could be generated by asking this effort to be minimized.
The details about the model, and its components, can be found here
http://mkweb.bcgsc.ca/carpalx/?typing_effort
While many optimized layouts for English exist, fewer are available for non-English typists. The typing effort model can be applied to discover the best layout for non-English texts.
One benefit of a generalized model is the ability to incrementally improve a layout. For those not yet ready to jump from the QWERTY ship, I suggest the partially optimized layouts, in which either 5 or 10 most efficient key swaps were made.
http://mkweb.bcgsc.ca/carpalx/?partial_optimization
Of course the ultimate question for English typists is - can Colemak be improved? If so, by how much? And, if by little, is there any point in switching.
These two layouts attempt to address this
http://mkweb.bcgsc.ca/carpalx/?improving_colemak
Both of these layouts (PBFMWJ which rearranges ZXCV, and GYLMWP which does not) have significantly lower hand asymmetry than Colemak (1-2% vs 6%), somewhat lessen the burden on the pinky (14-15% vs 16), and make less use of the bottom row (5-7% vs 9%). The major component of typing effort decrease (about 5% lower than Colemak) is due to decreased use of the pinky and bottom row, which in the model are penalized.
The improvement introduced by these layouts is incremental, of course, since Colemak is already heavily optimized. For some, the improvement may not be seen as such, because typing preferences vary and minor details of layouts so close to the edge of optimum are arguable.
If your desire is to lessen the use of the pinky, at the expense of slightly increasing finger travel distance, then the fully optimized layouts (these vary based on whether ; is remapped and whether zxcv is fixed) are ideal
http://mkweb.bcgsc.ca/carpalx/?full_optimization
If, on the other hand, you prefer shorter finger travel at the expense of pinky use then the two Colemak improvements suit nicely.
In conclusion, while Colemak does not minimize any typing parameter (e.g. Hallingstad's Arensito has the lowest finger travel distance of all popular alternatives that I looked at), it does strike an excellent balance with many parameters close to a global minimum. Whether it is worthwhile to incrementally minimize the parameters further in practise is debatable, though it's an interesting academic problem. However, applying the carpalx model to non-English texts should be fruitful in generating optimized layouts for other languages.