Everything You Ever Wanted to Know About Word Prediction...But Were Afraid to Ask

By Ed Salisbury, AT Specialist

There is a wide variety of software on the market today designed to assist people with disabilities with writing. These programs all seem very similar, but with a large difference in price. It is important to understand what features each program contains and what features best suit the particular needs of the person using the computer.

There are four main types of software that will assist a person with writing. Many people use the terms interchangeably, but each type is considerably different. The first type of assistive writing software is abbreviation expansion. This software allows long strings of text to be accessed by typing only a short abbreviation. For example, the words "Occupational Therapist" can be set up as the abbreviation "OT." Whenever OT is typed, the computer will automatically expand it into Occupational Therapist. Abbreviations can be set up for a person's name, address, or even common sayings. Abbreviation expansion programs can significantly decrease the number of keystrokes necessary to type a document and therefore speed up typing and lessen fatigue. The main advantage of abbreviation expansion programs is their low cost. Most of the latest versions of office level word processors include an abbreviation expansion feature. Shareware abbreviation expansion programs can also be downloaded from the Internet, on-line services, or bulletin boards for Macintosh and PC compatible computers. A disadvantage of using this type of software, especially with someone with a learning disability or head injury, is the high memory load on the typist to remember all of the abbreviations. Also, each and every abbreviation with its expansion must be programmed into the computer. This could be very time consuming if a large number of abbreviations is desired.

The second type of software designed to assist a person with writing is word completion. Word completion software helps the typist finish words by presenting him or her with a list of possible word choices. For example, if a person types a "T" as the first word of a sentence, he or she would most likely be presented with a list of choices including:

1. The
2. This
3. That
4. These
5. Those

The typist would then choose the number of the correct word choice. The word would be completed followed by a space. If the correct word is not in the list, the second letter of the word would have to be typed. The list would then change to reveal new choices. Most words will appear in the word list upon typing the second or third letter. Better word completion programs remember what words the typist uses often and suggests those words more frequently and higher in the list. Conversely, many word completion programs include a word frequency model that cannot be adapted to a person's typing style. Some word completion programs suggest suffixes like -ing, -ly, and -er after the word is completed. The advantages of good word completion programs include keystroke reduction for people with physical impairments and assistance with spelling for those people with learning disabilities. Many people with learning disabilities have the ability to initiate a word and recognize it when it is presented to them. A disadvantage of word completion programs is that they generally do not save the typist keystrokes on one-, two-, and three-letter words.

The third type of program is called word prediction. Some manufacturers refer to their software as word prediction, when it is in fact word completion. Word prediction programs operate in much the same way as word completion with one exception: word prediction programs suggest, or predict, the best next-word choices after the previous word has been completed. For example, after the typist chooses the word "This" from the choice list, he or she is most likely presented with a list of words with "is" as the first choice. Selecting a "1" at this point would cause the computer to type the word "is" followed by a space and a list of new next-word choices.

Unlike word completion programs, keystrokes are saved even when typing one-letter words. Many word prediction programs include an abbreviation expansion feature. With this type of software, abbreviations are included with the words in the choice list. When the abbreviation is selected from the list, it is automatically expanded into the full string of text, thus saving more keystrokes.

A consideration to be aware of when purchasing a word completion or word prediction program is how the program lets the user customize the way in which the choice list is presented. The typist should be allowed to change the number of words presented to him or her in the list. A person who finds typing slow and tedious may want a longer choice list as a means of further reducing the number of keystrokes he or she must make to complete a word. A person with a learning disability, on the other hand, may want a smaller choice list to avoid lost time searching through the list for the intended word. Another feature that should be customizable is the method for ordering words in the list. The most common method of presenting the words in the choice list is by word frequency. This word frequency can be based on the program's built-in model or on the program actually learning what words the typist uses most often and what words they generally follow. Some typists, though, may want a list that is ordered alphabetically. It has been suggested that the ideal ordering for a list of words is by word length with the shortest word at the top of the list. This arrangement would allow the typist to quickly locate the desired word even if it is contained in a long choice list.

There are many assistive writing software programs available with a variety of features and at a wide range of prices. With a basic understanding of how these programs operate, the selection process will not seem so overwhelming. Few programs offer all of the features discussed, and the ones that offer the most are not always the most expensive. For more information on assistive writing programs or assistance sorting through the many features, contact your local ATRC.