You do not have permission to edit this page, for the following reasons:

This IP address has been blocked from editing Wikipedia.
This does not affect your ability to read Wikipedia pages.
Most people who see this message have done nothing wrong. Some kinds of blocks restrict editing from specific service providers or telecom companies in response to recent abuse or vandalism, and can sometimes affect other users who are unrelated to that abuse. Review the information below for assistance if you do not believe that you have done anything wrong.

The IP address or range 44.201.0.0/16 has been blocked (disabled) by ‪ST47‬ for the following reason(s):

The IP address that you are currently using has been blocked because it is believed to be a web host provider. To prevent abuse, web hosts may be blocked from editing Wikipedia.
You will not be able to edit Wikipedia using a web host provider because it hides your IP address, much like a proxy or VPN.
We recommend that you attempt to use another connection to edit. For example, if you use a proxy or VPN to connect to the internet, turn it off when editing Wikipedia. If you edit using a mobile connection, try using a Wi-Fi connection, and vice versa. If you are using a corporate internet connection, switch to a different Wi-Fi network. If you have a Wikipedia account, please log in.
If you do not have any other way to edit Wikipedia, you will need to request an IP block exemption.

How to appeal if you are confident that your connection does not use a web host's IP address:
If you are confident that you are not using a web host, you may appeal this block by adding the following text on your talk page: ((unblock|reason=Caught by a web host block but this host or IP is not a web host. My IP address is _______. Place any further information here. ~~~~)). You must fill in the blank with your IP address for this block to be investigated. Your IP address can be determined here. Alternatively, if you wish to keep your IP address private you can use the unblock ticket request system. There are several reasons you might be editing using the IP address of a web host (such as if you are using VPN software or a business network); please use this method of appeal only if you think your IP address is in fact not a web host.

Administrators: The IP block exemption user right should only be applied to allow users to edit using web host in exceptional circumstances, and they should usually be directed to the functionaries team via email. If you intend to give the IPBE user right, a CheckUser needs to take a look at the account. This can be requested most easily at SPI Quick Checkuser Requests. Unblocking an IP or IP range with this template is highly discouraged without at least contacting the blocking administrator.

This block will expire on 23:54, 31 July 2024.

Even when blocked, you will usually still be able to edit your user talk page, as well as email administrators and other editors.

For information on how to proceed, please read the FAQ for blocked users and the guideline on block appeals. The guide to appealing blocks may also be helpful.

Other useful links: Blocking policy · Help:I have been blocked
Your IP address is in a range that has been blocked on all Wikimedia Foundation wikis. The block was made by ‪AntiCompositeNumber‬. The reason given is Open proxy/Webhost: Visit the FAQ if you are affected .
- Start of block: 13:55, 18 August 2022
- Expiry of block: 13:55, 18 April 2025
Your current IP address is 44.201.219.156. The blocked range is 44.201.0.0/16. Please include all above details in any queries you make. If you believe you were blocked by mistake, you can find additional information and instructions in the No open proxies global policy. Otherwise, to discuss the block please post a request for review on Meta-Wiki. You could also send an email to the stewards VRT queue at stewards@wikimedia.org including all above details.

You can view and copy the source of this page:

((Short description|T9 is a predictive text technology for mobile phones with a 3×4 numeric keypad))
((refimprove|date=February 2019))
((pic|T9 Text Input logo.svg|Logo of T9))
'''T9''' is a [[predictive text]] technology for [[mobile phone]]s (specifically those that contain a [[Telephone keypad|3×4 numeric keypad]]), originally developed by [[Tegic|Tegic Communications]], now part of [[Nuance Communications]]. T9 stands for ''Text on 9 keys.''<ref>[http://www.nuance.com/news/pressreleases/2007/20070824_tegic.asp Nuance Communications press release] ((Webarchive|url=https://web.archive.org/web/20071013180544/http://www.nuance.com/news/pressreleases/2007/20070824_tegic.asp |date=2007-10-13 )) (2007).</ref>

T9 was used on phones from [[Verizon (mobile network)|Verizon]], [[NEC]], [[Nokia]], [[Samsung Electronics]], [[Siemens]], [[Sony Mobile]], [[Sanyo]], [[SAGEM]] and others, as well as [[Personal digital assistant|PDA]]s such as [[Avigo]] during the late 1990s. The main competing technologies include [[iTap]] created by [[Motorola Mobile Devices|Motorola]], [[SureType]] created by [[Research In Motion|RIM]], Eatoni's [[LetterWise]] and WordWise, and Intelab's [[Tauto]]. It still is used on niche products as Punkt mp-02.

T9 is not available on Apple devices but is available on certain inexpensive phones without a touchscreen, and modern [[Android (operating system)|Android]] phones where it can be used to dial contacts by spelling the name of the contact one is trying to call.

The technology was protected by multiple US patents, but they have since expired.<ref>((Patent|US|5818437))</ref><ref>((Patent|US|5953541))</ref><ref>((Patent|US|6011554))</ref><ref>((Patent|US|4650349))</ref>

== Design ==

[[File:Telephone-keypad2.svg|thumb|Keypad used by T9.]]
T9's objective is to make it easier to enter [[text message]]s. It allows words to be formed by a single keypress for each letter, which is an enormous improvement over the [[multi-tap]] approach used in conventional mobile phone text entry at the time, in which several letters are associated with each key, and selecting one letter often requires multiple keypresses.

T9 combines the groups of letters on each phone key with a fast-access [[dictionary]] of words. It will then look up in the dictionary all words corresponding to the sequence of keypresses and order them by frequency of use. As T9 "gains familiarity" with the words and phrases the user commonly uses, it speeds up the process by offering the most frequently used words first and then letting the user access other choices with one or more presses of a predefined "Next" key.

The dictionary is expandable. After introducing a new word, the next time the user tries to produce that word, T9 adds it to the predictive dictionary. The user database (UDB) can be expanded via [[multi-tap]]. The implementation of the user database is dependent on the version of T9 and how T9 is actually integrated on the device. Some phone manufacturers supply a permanent user database, while others do so for the duration of the session.

== Features ==
Some T9 implementations feature ''smart punctuation''. This feature allows the user to insert sentence and word punctuation using the '1'-key. Depending on the context, smart punctuation inserts sentence punctuation (period or 'full stop') or embedded punctuation (period or hyphen) or word punctuation (apostrophe in can't, won't, isn't, and the possessive '' 's''). Depending on the language, T9 also supports word breaking after punctuation to support [[clitic]]s such as ''l' '' and ''n' ''in French and '' 's'' in English.

The UDB is an optional feature that allows words that were explicitly entered by the user to be stored for reference. The number of words stored depend on the implementation and the language.

In later versions of T9, the order of the words presented is adapted to the usage pattern. For instance, in English, 4663 matches "good", "home", "gone", "hood", etc. Such combinations are known as ''[[textonym]]s''; e.g., "home" is referred to as a ''textonym'' of "good". T9 is encoded to prefer the word that its programmers determined to be the most common textonym, such as "good" over "home" or "gone", "hand" over "game", or "bad" over "cad" or "ace".

When the user tends to use "home" more often than "good", eventually the two words switch position, and "home" is presented as the default option instead. Information about common word combinations can also be learned and stored for predictions (so, "I'm feeling" followed by 4663 will be offered as "good" instead of "home", whereas "I went back" and 4663 would be "home", not "good").

For words entered by the user, [[word completion]] can be enabled. When the user enters matching keypresses, in addition to words and stems, the system also provides completions.

In later versions of T9, the user can select a primary and secondary language and access matches from both languages. This enables users to write messages in their native language, as well as a foreign one.

Some implementations learn commonly used word pairs and provide word prediction (e.g. if one often writes "eat food", after entering "eat" the phone will suggest "food", which can be confirmed by pressing Next).

T9 can automatically recognize and correct typing/texting errors, by looking at neighboring keys on the keypad to determine an incorrect keypress. For example, the word "testing" is entered with the key combination "8378464". Entering the same number but with two incorrect keypresses of neighboring keys, e.g. "8278494", results in T9 suggesting the words "tasting" (8278464), "testing" (8378464), and "tapping" (8277464).

== Algorithm ==
In order to achieve compression ratios of close to 1 byte per word, T9 uses an optimized [[algorithm]] that maintains word order and partial words (also known as stems); however, because of this compression, it over-generates words that are sometimes visible as "junk words". This is a side effect of the requirements for small database sizes on the lower end embedded devices.((citation needed|date=February 2019))

== Examples ==
On a phone with a numeric keypad, each time a key (1-9) is pressed (when in a text field), the algorithm returns a guess for what letters are most likely for the keys pressed to that point. For example, to enter the word 'the', the user would press 8 then 4 then 3, and the display would display 't' then 'th' then 'the'. If the less-common word 'fore' is intended (3673) the predictive algorithm may select 'Ford'. Pressing the 'next' key (typically the '*' key) might bring up 'dose', and finally 'fore'. If 'fore' is selected, then the next time the user presses the sequence 3673, fore will be more likely to be the first word displayed. If the word "Felix" is intended, however, when entering 33549, the display shows '<u>E</u>', then 'De', 'Del', 'Deli', and '<u>F</u>elix.' This is an example of a letter changing while entering words.

== Successors ==
[[File:T9 on an LG in 2020.png|alt=Image of T9 on screen of an LG V60|thumb|491x491px|Screenshot, LG V60 Android, using T9 predictive text in "4x3" keyboard format. Screenshot taken 2020/08/06]]
Many smart keyboards now exist, such as [[Swype]] or [[Swiftkey]], that have taken the idea of T9 and married it with the advanced touchscreen technology found in [[Android phone]]s and [[iPhones]]. These advances have made T9 obsolete in newer cellphones for many users, since it is predicated on the use of a keypad with nothing besides numbers, the asterisk and the pound key (known as the hash key in Commonwealth countries). Many features, such as predictive text, have been adopted by and improved by future generations of keyboard software. However, T9 remains viable. For example, those with larger fingertips still use the T9 based keyboard on smartphones for text entry, because key press accuracy increases with the larger screen area per key on a numeric-style 4×3 keyboard. Such T9 formats for text entry therefore remain available in all latest [as of August 2020] iterations of LG keyboards, certain Samsung keyboards, and third party T9 keyboards such as Go keyboard for Androids and Type Nine for iPhones, as shown on this LG V60.

== See also ==
* [[XT9]]
* [[LetterWise]]
* [[Predictive text]]
* [[Telephone keypad]]
* [[Phoneword]]

== References ==
((reflist))

== External links ==
*[https://web.archive.org/web/20170606190240/https://www.nuance.com/mobile/mobile-solutions/text-input-solutions/t9.html Nuance T9 Customer facing site]

[[Category:Natural language processing]]
[[Category:User interface techniques]]
[[Category:Nuance software]]
[[Category:Input methods for handheld devices]]

Pages transcluded onto the current version of this page (help):

T9 (predictive text) (edit)
Template:Ambox (view source) (template editor protected)
Template:Category handler (view source) (protected)
Template:Citation/make link (view source) (protected)
Template:Citation/styles.css (view source) (template editor protected)
Template:Citation needed (view source) (protected)
Template:Cite patent (view source) (template editor protected)
Template:Cite patent/core (view source) (template editor protected)
Template:Delink (view source) (protected)
Template:Find sources mainspace (view source) (template editor protected)
Template:Fix (view source) (protected)
Template:Fix/category (view source) (protected)
Template:Main other (view source) (protected)
Template:More citations needed (view source) (template editor protected)
Template:Pagetype (view source) (protected)
Template:Patent (view source) (semi-protected)
Template:Pic (edit)
Template:Plain image with caption (view source) (semi-protected)
Template:Plain image with caption/styles.css (view source) (semi-protected)
Template:Refimprove (view source) (template editor protected)
Template:Reflist (view source) (protected)
Template:Reflist/styles.css (view source) (protected)
Template:SDcat (view source) (protected)
Template:Short description (view source) (protected)
Template:Short description/lowercasecheck (view source) (protected)
Template:Str number/trim (view source) (protected)
Template:Webarchive (view source) (template editor protected)
Module:Arguments (view source) (protected)
Module:Category handler (view source) (protected)
Module:Category handler/blacklist (view source) (protected)
Module:Category handler/config (view source) (protected)
Module:Category handler/data (view source) (protected)
Module:Category handler/shared (view source) (protected)
Module:Check for unknown parameters (view source) (protected)
Module:Delink (view source) (protected)
Module:Disambiguation/templates (view source) (protected)
Module:Find sources (view source) (template editor protected)
Module:Find sources/config (view source) (template editor protected)
Module:Find sources/links (view source) (template editor protected)
Module:Find sources/templates/Find sources mainspace (view source) (template editor protected)
Module:Message box (view source) (protected)
Module:Message box/ambox.css (view source) (protected)
Module:Message box/configuration (view source) (protected)
Module:Namespace detect/config (view source) (protected)
Module:Namespace detect/data (view source) (protected)
Module:Pagetype (view source) (protected)
Module:Pagetype/config (view source) (protected)
Module:Pagetype/disambiguation (view source) (protected)
Module:Pagetype/setindex (view source) (protected)
Module:Pagetype/softredirect (view source) (protected)
Module:SDcat (view source) (protected)
Module:String (view source) (protected)
Module:Unsubst (view source) (protected)
Module:Webarchive (view source) (template editor protected)
Module:Webarchive/data (view source) (template editor protected)
Module:Wikitext Parsing (view source) (protected)
Module:Yesno (view source) (protected)

Return to T9 (predictive text).

Retrieved from "https://en.wikipedia.org/wiki/T9_(predictive_text)"