What is t9?

T9™ is a technology built to help assist people typing on cellular telephones. It uses set word lists to try to predict what words people are trying to type, allowing them to easily and quickly move through words with minimal keystrokes. Because of the awkwardness of typing on a small keypad, T9™ was developed to help push texting technologies, which provide a not-inconsiderable source of income for cell phone providers.

The T9™ technology was developed in 1998 by Tegic Communications, and patented as US Patent 5818437 as a Reduced Keyboard Disambiguating Computer. Tegic was eventually acquired by Nuance Communications, the company that produces Dragon NaturallySpeaking, PaperPort, Omni Page, and PDF Converter in the consumer realm, and a number of transcription and speech recognition packages for the business world. The technology is the most-used predictive text technology, and is licensed by many major cell phone providers, including Nokia, Sony Ericsson, LG, Sanyo, Samsung, and Siemens. The two major competitors to T9™ are Motorola’s iTap and RIM’s SureType®, both of which do roughly the same thing, but in a different way.

The basic idea behind T9™, which stands for Text on 9 Keys, is to allow users to type out complex text using only the nine keys of a cell phone. Usually, in order to type a given letter, a user would have to strike the key as many times as was needed to get to the correct letter. For example, striking the 2 key twice would render a B, while striking it three times would render a C. This means that to type a word like clash one would have to hit twelve keys: the 2 key three times, the 5 key three times, the 2 key once, the 7 key three times, and the 4 key twice. This of course can get to be quite time consuming and frustrating when trying to type out long messages.

Using the T9™ system, however, the word clash could be typed out striking only five keys. As each key is hit, the T9™ technology checks its word list to see what words could possibly be made with those combinations of key strokes, and then puts the most common word first. If the word that comes up isn’t the desired word, simply pushing a Next key of some sort changes the entire word to the next most common word. For example, pushing the keys 5477 might make the word kiss appear, but pushing the Next button would change the word kiss to the word lips, which uses all of the same numbers, but is a slightly less common word, and so comes next in order on the word list.

One added feature of T9™ is that it learns as you use it. So, for example, commonly used phrases or words will begin to be auto-completed by the phone as you type them, helping to speed up things like common URLs or names. Similarly, words can be added to the T9™ lexicon, ensuring that the next type you type the name of your hometown it will auto-complete it for you.