In this way, the user can easily pass the chord keys, and get to functions such as predicted words or shift keys. Another chord keyboard that works very well is the Microwriter keyboard. This uses 5 keys, one for each finger of the hand. The code is based roughly on the shapes of the letters, and is one of the easiest of all codes to learn. This is the code that you do not need to learn.
Disambiguation uses a smaller number of cells, or keys, to represent the entire alphabet.
Each cell contains a number of characters, normally three. All that is necessary is to select the cells that contain the letters you need. The software then works out which possible letter combinations could be the start of a real word, and gives the user a set of predictions based on these. The main advantage of disambiguation to a switch user is the ability to scan the alphabet on a grid of 9 cells instead of 26, greatly reducing the scanning time for each character. When cell 1 is selected, the system knows that the word will begin with either A, B or C and will suggest some words beginning with these letters.