|
The Dvorak Simplified Keyboard ( ) is a keyboard layout patented in 1936 by Dr. August Dvorak and his brother-in-law, Dr. William Dealey. Over the years several slight variations were designed by the team led by Dvorak or by ANSI. These variations have been collectively or individually also called the Simplified Keyboard or American Simplified Keyboard but they all have come to be commonly known as the Dvorak keyboard or Dvorak layout. Dvorak proponents claim the Dvorak layout uses less finger motion and reduces errors compared to the standard QWERTY keyboard. This reduction in finger distance traveled is claimed to permit faster rates of typing while reducing repetitive strain injuries,〔("Alternative Keyboard Layouts" ). Microsoft. Retrieved March 30, 2012.〕 though this has been called into question〔 and their criticism has in turn also been called into question. Although the Dvorak Simplified Keyboard (DSK) has failed to replace the QWERTY keyboard, most major modern operating systems (such as Windows,〔(【引用サイトリンク】title=Alternative Keyboard Layouts )〕 OS X, Linux, Android, Chrome OS, iOS (via a third-party keyboard), and BSD) allow a user to switch to the Dvorak layout. Currently BlackBerry 10 and Windows Phone do not support a system-wide, touchscreen, Dvorak keyboard. ==Overview== The Dvorak layout was designed to replace the QWERTY keyboard layout (the ''de facto'' standard keyboard layout, so named for the starting letters in the top row). The Dvorak layout was designed in the belief that it would significantly increase typing speeds over the QWERTY layout. Dvorak believed that there were many problems with the original QWERTY keyboard, claiming that it was a problem that: * Many common letter combinations require awkward finger motions. * Many common letter combinations require a finger to jump over the home row. * Many common letter combinations are typed with one hand. (e.g. was, were) * Most typing is done with the left hand, which for most people is not the dominant hand. * About 16% of typing is done on the lower row, 52% on the top row and only 32% on the home row. Dvorak studied letter frequencies and the physiology of people's hands and created a layout to alleviate the problems he believed were part of the QWERTY layout. The layout he created adheres to these principles:〔 * Letters should be typed by alternating between hands (which makes typing more rhythmic, increases speed, reduces error, and reduces fatigue). On the Dvorak, vowels are all on the left home row, the most used symbols are on the left, while the most used consonants are on the right. * For maximum speed and efficiency, the most common letters and bigrams should be the easiest to type. This means that they should be on the home row, which is where the fingers rest, and under the strongest fingers (Thus, about 70% of keyboard strokes on the Dvorak Simplified Keyboard are done on the home row and only 22% and 8% on the top and bottom rows respectively). * The least common letters should be on the bottom row which is the hardest row to reach. * The right hand should do more of the typing because most people are right-handed. The Dvorak layout is intended for the English language. In other European languages, letter frequencies, letter sequences, and bigrams differ from those of English. Also, many languages have letters that do not occur in English. For non-English use, these differences lessen the supposed advantages of the original Dvorak keyboard. However, the Dvorak principles have been applied to the design of keyboards for other languages, though the primary keyboards used by most countries are based on the QWERTY design. The layout was completed in 1932 and was granted in 1936.〔(【引用サイトリンク】title=US patent # 2040248 )〕 The American National Standards Institute (ANSI) designated the Dvorak keyboard as an alternative standard keyboard layout in 1982; the standard is INCITS 207-1991 (R2007) (previously X4.22-1983, X3.207:1991),〔(【引用サイトリンク】title=ANSI INCITS 207-1991 (R2007) )〕 "Alternate Keyboard Arrangement for Alphanumeric Machines". The original ANSI Dvorak layout was available as a factory-supplied option on the original IBM Selectric typewriter. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dvorak Simplified Keyboard」の詳細全文を読む スポンサード リンク
|