Richard Simpson and Heidi Horstmann Koester
Word prediction is a technique often used by individuals with disabilities as a means of increasing the rate with which they can enter text into a computer by reducing the number of keystrokes entered per word. A word prediction system typically operates by presenting a list of ``best guesses'' for the word the user is currently entering. As the user continues to enter letters, the system updates the list of word predictions to conform to the user’s input. When the word the user is entering is displayed on the list, the user can select the word with one keystroke (often, one of the number keys on the keyboard), and the system will then complete the word for the user. There are several parameters defining the word prediction interface that can have an effect on a user’s text entry rate, including: the number of words displayed in the prediction list, the minimum length of words displayed in the prediction list, the number of keystrokes that must be entered before predictions are displayed, and the number of keystrokes that are entered before the prediction list is removed.