QWERTY
QWERTY is the modern-day layout of letters on most English language computer keyboards and typewriter keyboards. It takes its name from the first six letters shown on the keyboard's top row of letters.
The Qwerty Layout
The QWERTY design was patented by Christopher Sholes in 1868, and sold to Remington in 1873, when it first appeared in typewriters. (This patent has since expired.)
Frequently-used pairs of letters were separated in an attempt to stop the typebars from intertwining and becoming stuck, thus forcing the typist to manually unstick the typebars and also frequently blotting the document. (The home row (ASDFGHJKL) of the QWERTY layout is thought to be a remnant of the old alphabetical layout that QWERTY replaced.) It also alternated keys between hands, allowing one hand to move into position while the other hand strikes a key. This sped up both the original double-handed hunt-and-peck technique and the later touch typing technique; however, single-handed words such as "stewardess" and "monopoly" show flaws in the alternation.
Tests have shown that other arrangements of keys may lead to slightly more efficient typing of typical English text, and the Dvorak Simplified Keyboard arrangement (1936) has had some success in that regard, but the QWERTY arrangement remains the most popular, largely due both to market inertia and to tests showing little significant performance difference between those who first learned to type on QWERTY and those who first learned to type on Dvorak (In fact, Sholes himself patented a different arrangement more similar to Dvorak's, but it never became popular).
These tests are criticized as being inconclusive. Many users of Dvorak say that QWERTY is far less ergonomic than Dvorak because QWERTY spreads the most commonly used letters out around the entire keyboard while Dvorak puts them in the home row.
It is important to consider keybindings as well in comparison with other keyboard layouts. Many QWERTY users have a 'tactile memory' of sorts that lay out finger positions for common shortcuts such as Ctrl-c, Ctrl-x, Ctrl-v, which are all in the bottom row. However in other layouts this alignment may be disturbed. Another example is the vi editor. Arrow keys are usually mapped to h, j, k, and l, all in a row, however this alignment is disturbed in the use of another layout. Retraining this 'tactile memory' for keyboard shortcuts takes more time than relearning mere key layouts -- users may want to become used to the new positions of the shortcut letters.
Minor changes to the arrangement are made for other languages; for example, German keyboards interchange the "Z" and "Y" keys because Z and A often appear next to each other in the German language; consecutively, they are known as QWERTZ keyboards. French keyboards interchange both "Z" and "Y" and "Q" and "A" and are known as AZERTY keyboards.
Asdfjkl, a variation of the home row keys (ASDFGHJKL), is used to symbolize nonsensical typos.
