Word prediction
Encyclopedia
Word prediction is the provision of words that are frequently used in response to a user's keystrokes.
generally produce speech at a rate that is less than 10% as fast as people who use oral speech.
as the writer selects the first letter or letters of a word, the program predicts one or more possible words as choices. If the word that the user wants is not predicted, the writer must enter the next letter of the word. At this time, the word choice(s) is altered so that the words provided begin with the same letters as those that have been selected. When the word that the user wants appears it is selected, and the word is inserted into the text. In another form of word prediction, words most likely to follow the just written one are predicted, based on recent word pairs used. Word prediction uses language modeling, where within a set vocabulary the words are most likely to occur are calculated. Along with language modeling, basic word prediction on AAC devices is often coupled with a recency model, where words that are used more frequently by the AAC user are more likely to be predicted. Word prediction software often also allows the user to enter their own words into the word prediction dictionaries either directly, or by "learning" words that have been written.
and requirement to move eye gaze from the keyboard to the monitor.
In order to reduce this cognitive load, parameters such as reducing the list to five likely words, and having a vertical layout of those words may be used. The vertical layout is meant to keep head and eye movements to a minimum, and also gives additional visual cues because the word length becomes apparent. Although many software developers believe that if the word prediction list follows the cursor
, that this will reduce eye movements, in a study of children with Spina Bifida
by Tam, Reid, O'Keefe & Nauman (2002) it was shown that typing was more accurate, and that the children also preferred when the list appeared at the bottom edge of the screen, at the midline. Several studies have found that word prediction performance and satisfaction increases when the word list is closer to the keyboard, because of the decreased amount of eye-movements needed.
Software with word prediction is produced by multiple manufacturers. The software can be bought as an add-on to common programs such as Microsoft Word
(for example, WordQ+SpeakQ
, Typing Assistant, Co:Writer, Wivik), or as one of many features on an AAC device (PRC's Pathfinder, Dynavox Systems, Saltillo’s ChatPC products).
Purpose
The original purpose of word prediction software was to help people with physical disabilities increase their typing speed, as well as to help them decrease the number of keystrokes needed in order to complete a word or a sentence. The need to increase speed is noted by the fact that people who use speech generating devicesVoice output communication aid
Speech generating devices , also known as voice output communication aids , are electronic augmentative and alternative communication systems that enable individuals with severe speech impairment to verbally communicate their needs.Speech generating systems may be dedicated devices developed...
generally produce speech at a rate that is less than 10% as fast as people who use oral speech.
Description
In one form of word prediction, word completionWord completion
Word completion is a common feature in web browsers and similar text entry contexts. When a user begins the entry of a frequently-used word, the computer automatically completes it, or proposes a list of choices....
as the writer selects the first letter or letters of a word, the program predicts one or more possible words as choices. If the word that the user wants is not predicted, the writer must enter the next letter of the word. At this time, the word choice(s) is altered so that the words provided begin with the same letters as those that have been selected. When the word that the user wants appears it is selected, and the word is inserted into the text. In another form of word prediction, words most likely to follow the just written one are predicted, based on recent word pairs used. Word prediction uses language modeling, where within a set vocabulary the words are most likely to occur are calculated. Along with language modeling, basic word prediction on AAC devices is often coupled with a recency model, where words that are used more frequently by the AAC user are more likely to be predicted. Word prediction software often also allows the user to enter their own words into the word prediction dictionaries either directly, or by "learning" words that have been written.
Research
Although research has shown that word prediction software does decrease the number of keystrokes needed and improves the written productivity of children with disabilities, there are mixed results as to whether or not word prediction actually increases speed of output. It is thought that the reason why word prediction does not always increase the rate of text entry is because of the increased cognitive loadCognitive load
The term cognitive load is used in cognitive psychology to illustrate the load related to the executive control of working memory . Theories contend that during complex learning activities the amount of information and interactions that must be processed simultaneously can either under-load, or...
and requirement to move eye gaze from the keyboard to the monitor.
In order to reduce this cognitive load, parameters such as reducing the list to five likely words, and having a vertical layout of those words may be used. The vertical layout is meant to keep head and eye movements to a minimum, and also gives additional visual cues because the word length becomes apparent. Although many software developers believe that if the word prediction list follows the cursor
Cursor (computers)
In computing, a cursor is an indicator used to show the position on a computer monitor or other display device that will respond to input from a text input or pointing device. The flashing text cursor may be referred to as a caret in some cases...
, that this will reduce eye movements, in a study of children with Spina Bifida
Spina bifida
Spina bifida is a developmental congenital disorder caused by the incomplete closing of the embryonic neural tube. Some vertebrae overlying the spinal cord are not fully formed and remain unfused and open. If the opening is large enough, this allows a portion of the spinal cord to protrude through...
by Tam, Reid, O'Keefe & Nauman (2002) it was shown that typing was more accurate, and that the children also preferred when the list appeared at the bottom edge of the screen, at the midline. Several studies have found that word prediction performance and satisfaction increases when the word list is closer to the keyboard, because of the decreased amount of eye-movements needed.
Software with word prediction is produced by multiple manufacturers. The software can be bought as an add-on to common programs such as Microsoft Word
Microsoft Word
Microsoft Word is a word processor designed by Microsoft. It was first released in 1983 under the name Multi-Tool Word for Xenix systems. Subsequent versions were later written for several other platforms including IBM PCs running DOS , the Apple Macintosh , the AT&T Unix PC , Atari ST , SCO UNIX,...
(for example, WordQ+SpeakQ
WordQ+SpeakQ
WordQ® is assistive technology software developed by Quillsoft Ltd. and Holland Bloorview Kids Rehabilitation Hospital, represented by goQSoftware and distributed in the United States by ST4Learning and in Canada by Strategic Transitions. WordQ's main purpose is helping individuals who struggle...
, Typing Assistant, Co:Writer, Wivik), or as one of many features on an AAC device (PRC's Pathfinder, Dynavox Systems, Saltillo’s ChatPC products).