The Dvorak keyboard

Article taken from http://www.mit.edu/~jcb/Dvorak/

The Dvorak keyboard, named for its inventor, Dr. August Dvorak, was designed with the goal of maximizing typing efficiency. For over a century, typists have been using the qwerty keyboard arrangement, a hack that was implemented to work around the mechanical limitations of early typewriters.

Contrary to popular opinion, the qwerty design was not actually invented to slow typists down. Rather, the layout was intended to place common two-letter combinations on opposite sides of the keyboard. On manual typewriters, each key is mechanically connected to a lever that has the reversed image of a letter on it. If a typist were to hit two keys on the same side of the keyboard in rapid succession, the second lever on its way up would hit the first on its way down, the keys would become stuck together, and the typist would have to stop typing and unstick the keys. The qwerty layout was a clever design that minimized this problem. However, now that most of us use computers (or electric typewriters that don't use levers), the problem of keys jamming is no longer a consideration. Also, computers now enable us to switch layouts while continuing to use the same equipment.

Most people learn to type on a qwerty keyboard. New typists learn the qwerty arrangement because that's most likely what they'll encounter on the existing equipment they'll be using; new equipment is standardized to the qwerty arrangement because that's what the vast majority of us know. Most people are reluctant to switch because they're afraid of how long it will take them to learn the new arrangement, and of the additional effort of having to switch layouts on all of the equipment they might encounter.

Dvorak's Claims

According to Dvorak, prior to World War II, researchers had found that after three years of typing instruction, the average typing student's speed was 47 net words per minute (NWPM). Since typists were scarce during the war, the U.S. Navy selected fourteen typists for a 1944 study to assess whether Dvorak retraining would be feasible. Dvorak found that it took an average of only 52 hours of training for those typists' speeds on the Dvorak keyboard to reach their average speeds on the qwerty keyboard. By the end of the study their Dvorak speeds were 74 percent faster than their qwerty speeds, and their accuracies had increased by 68 percent.

Dvorak attributed the increase in accuracy to the fact that on keyboard, that the most common digraphs (two-letter combinations, such as "ed") in English would occur with a minimum of "hurdling" (having to jump over a key as if it were a hurdle), and would use stronger fingers rather than weaker ones. Dvorak estimated that the fingers of an average typist in his day travelled between 12 and 20 miles on a qwerty keyboard; the same text on a Dvorak keyboard would require only about one mile of travel. Dvorak believed that hurdling and awkward keystroke combinations were responsible for most of the common errors typists make. His list of the most common typing errors on the Dvorak and qwerty keyboards is interesting.

Unfortunately, subsequent investigation has shown that at best, the experiments in the Navy study were biased, and at worst, fabricated. See Typing Errors, from the June 1996 issue of Reason Magazine for a thorough discussion of this topic, as well as more information about the early history of the typewriter and the qwerty keyboard. In the mid 1950s, U.S. Government's General Services Administration commissioned a study by Earle Strong to confirm Dvorak's results. Strong's study, which included proper controls and which was set up to allow direct comparison of qwerty and Dvorak data, found that after sufficient training, Dvorak typists were able to match their previous qwerty speeds, but not surpass them. Furthermore, additional qwerty training for qwerty typists resulted in a greater increase in speed than additional Dvorak training for Dvorak typists who typed at a similar rate. These results would suggest that Dvorak's claims of faster and more efficient typing are bogus, and switching layouts on the basis of speed and efficiency would not make sense.