Handheld electronic device providing a learning function to facilitate correction of erroneous text entry in environment of text requiring multiple sequential actuations of the same key, and associated method

[0001] 1. Field

[0002] The disclosed and claimed concept relates generally to handheld electronic devices and, more particularly, to a handheld electronic device having a reduced keyboard and a text input disambiguation function that can provide corrective proposed input during erroneous text entry.

[0003] 2. Background Information

[0004] Numerous types of handheld electronic devices are known. Examples of such handheld electronic devices include, for instance, personal data assistants (PDAs), handheld computers, two-way pagers, cellular telephones, and the like. Many handheld electronic devices also feature wireless communication capability, although many such handheld electronic devices are stand-alone devices that are functional without communication with other devices.

[0005] Such handheld electronic devices are generally intended to be portable, and thus are of a relatively compact configuration in which keys and other input structures often perform multiple functions under certain circumstances or may otherwise have multiple aspects or features assigned thereto. With advances in technology, handheld electronic devices are built to have progressively smaller form factors yet have progressively greater numbers of applications and features resident thereon. As a practical matter, the keys of a keypad can only be reduced to a certain small size before the keys become relatively unusable. In order to enable text entry, however, a keypad must be capable of entering all twenty-six letters of the Latin alphabet, for instance, as well as appropriate punctuation and other symbols.

[0006] One way of providing numerous letters in a small space has been to provide a “reduced keyboard” in which multiple letters, symbols, and/or digits, and the like, are assigned to any given key. For example, a touch-tone telephone includes a reduced keypad by providing twelve keys, of which ten have digits thereon, and of these ten keys eight have Latin letters assigned thereto. For instance, one of the keys includes the digit “2” as well as the letters “A”, “B”, and “C”. Other known reduced keyboards have included other arrangements of keys, letters, symbols, digits, and the like. Since a single actuation of such a key potentially could be intended by the user to refer to any of the letters “A”, “B”, and “C”, and potentially could also be intended to refer to the digit “2”, the input generally is an ambiguous input and is in need of some type of disambiguation in order to be useful for text entry purposes.

[0007] In order to enable a user to make use of the multiple letters, digits, and the like on any given key, numerous keystroke interpretation systems have been provided. For instance, a “multi-tap” system allows a user to substantially unambiguously specify a particular character on a key by pressing the same key a number of times equivalent to the position of the desired character on the key. Another exemplary keystroke interpretation system would include key chording, of which various types exist. For instance, a particular character can be entered by pressing two keys in succession or by pressing and holding first key while pressing a second key. Still another exemplary keystroke interpretation system would be a “press-and-hold/press-and-release” interpretation function in which a given key provides a first result if the key is pressed and immediately released, and provides a second result if the key is pressed and held for a short period of time. Another keystroke interpretation system that has been employed is a software-based text disambiguation function. In such a system, a user typically presses keys to which one or more characters have been assigned, generally pressing each key one time for each desired letter, and the disambiguation software attempt to predict the intended input.

[0008] Numerous such systems have been proposed, and while many have been generally effective for their intended purposes, such systems have not been without limitation. For instance, erroneous keying during text input on a device employing text disambiguation can result in output that bears no similarity to the input intended by the user.

[0009] It would be desirable to provide an improved handheld electronic device with a reduced keyboard that seeks to mimic a QWERTY keyboard experience or other particular keyboard experience. Such an improved handheld electronic device might also desirably be configured with enough features to enable text entry and other tasks with relative ease.

[0021] Similar numerals refer to similar parts throughout the specification.

[0022] An improved handheld electronic device 4 is indicated generally in FIG. 1 and is depicted schematically in FIG. 2. The exemplary handheld electronic device 4 includes a housing 6 upon which are disposed a processor unit that includes an input apparatus 8, an output apparatus 12, a processor 16, a memory 20, and at least a first routine. The processor 16 may be, for instance, and without limitation, a microprocessor (μP) and is responsive to inputs from the input apparatus 8 and provides output signals to the output apparatus 12. The processor 16 also interfaces with the memory 20. The processor 16 and the memory 20 together form a processor apparatus. Examples of handheld electronic devices are included in U.S. Pat. Nos. 6,452,588 and 6,489,950, which are incorporated by record herein.

[0023] As can be understood from FIG. 1, the input apparatus 8 includes a keypad 24 and a thumbwheel 32. As will be described in greater detail below, the keypad 24 is in the exemplary form of a reduced QWERTY keyboard including a plurality of keys 28 that serve as input members. It is noted, however, that the keypad 24 may be of other configurations, such as an AZERTY keyboard, a QWERTZ keyboard, or other keyboard arrangement, whether presently known or unknown, and either reduced or not reduced. As employed herein, the expression “reduced” and variations thereof in the context of a keyboard, a keypad, or other arrangement of input members, shall refer broadly to an arrangement in which at least one of the input members has assigned thereto a plurality of linguistic elements such as, for example, characters in the set of Latin letters, whereby an actuation of the at least one of the input members, without another input in combination therewith, is an ambiguous input since it could refer to more than one of the plurality of linguistic elements assigned thereto. As employed herein, the expression “linguistic element” and variations thereof shall refer broadly to any element that itself can be a language object or from which a language object can be constructed, identified, or otherwise obtained, and thus would include, for example and without limitation, characters, letters, strokes, ideograms, phonemes, morphemes, metaphones, digits, and the like. As employed herein, the expression “language object” and variations thereof shall refer broadly to any type of object that may be constructed, identified, or otherwise obtained from one or more linguistic elements, that can be used alone or in combination to generate text, and that would include, for example and without limitation, words, shortcuts, symbols, ideograms, and the like.

[0024] The system architecture of the handheld electronic device 4 advantageously is organized to be operable independent of the specific layout of the keypad 24. Accordingly, the system architecture of the handheld electronic device 4 can be employed in conjunction with virtually any keypad layout substantially without requiring any meaningful change in the system architecture. It is further noted that certain of the features set forth herein are usable on either or both of a reduced keyboard and a non-reduced keyboard.

[0025] The keys 28 are disposed on a front face of the housing 6, and the thumbwheel 32 is disposed at a side of the housing 6. The thumbwheel 32 can serve as another input member and is both rotatable, as is indicated by the arrow 34, to provide selection inputs to the processor 16, and also can be pressed in a direction generally toward the housing 6, as is indicated by the arrow 38, to provide another selection input to the processor 16.

[0026] As can further be seen in FIG. 1, many of the keys 28 include a number of linguistic elements 48 disposed thereon. As employed herein, the expression “a number of” and variations thereof shall refer broadly to any quantity, including a quantity of one. In the exemplary depiction of the keypad 24, many of the keys 28 include two linguistic elements, such as including a first linguistic element 52 and a second linguistic element 56 assigned thereto.

[0027] One of the keys 28 of the keypad 24 includes as the characters 48 thereof the letters “Q” and “W”, and an adjacent key 28 includes as the characters 48 thereof the letters “E” and “R”. It can be seen that the arrangement of the characters 48 on the keys 28 of the keypad 24 is generally of a QWERTY arrangement, albeit with many of the keys 28 including two of the characters 48.

[0028] The output apparatus 12 includes a display 60 upon which can be provided an output 64. An exemplary output 64 is depicted on the display 60 in FIG. 1. The output 64 includes a text component 68 and a variant component 72. The variant component 72 includes a default portion 76 and a variant portion 80. The display also includes a caret 84 that depicts generally where the next input from the input apparatus 8 will be received.

[0029] The text component 68 of the output 64 provides a depiction of the default portion 76 of the output 64 at a location on the display 60 where the text is being input. The variant component 72 is disposed generally in the vicinity of the text component 68 and provides, in addition to the default proposed output 76, a depiction of the various alternate text choices, i.e., alternates to the default proposed output 76, that are proposed by an input disambiguation function in response to an input sequence of key actuations of the keys 28.

[0030] As will be described in greater detail below, the default portion 76 is proposed by the disambiguation function as being the most likely disambiguated interpretation of the ambiguous input provided by the user. The variant portion 80 includes a predetermined quantity of alternate proposed interpretations of the same ambiguous input from which the user can select, if desired. It is noted that the exemplary variant portion 80 is depicted herein as extending vertically below the default portion 76, but it is understood that numerous other arrangements could be provided.

[0031] The memory 20 is depicted schematically in FIG. 2A. The memory 20 can be any of a variety of types of internal and/or external storage media such as, without limitation, RAM, ROM, EPROM(s), EEPROM(s), and the like that provide a storage register for data storage such as in the fashion of an internal storage area of a computer, and can be volatile memory or nonvolatile memory. The memory 20 additionally includes a number of routines depicted generally with the numeral 22 for the processing of data. The routines 22 can be in any of a variety of forms such as, without limitation, software, firmware, and the like. As will be explained in greater detail below, the routines 22 include the aforementioned disambiguation function as an application, as well as other routines.

[0032] As can be understood from FIG. 2A, the memory 20 additionally includes data stored and/or organized in a number of tables, sets, lists, and/or otherwise. Specifically, the memory 20 includes a generic word list 88, a new words database 92, one or more other data source 99, and a word frame table 49.

[0033] Stored within the various areas of the memory 20 are a number of language objects 100 and frequency objects 104. The language objects 100 generally are each associated with an associated frequency object 104. The language objects 100 include, in the present exemplary embodiment, a plurality of word objects 108 and a plurality of N-gram objects 112. The word objects 108 are generally representative of complete words within the language or are custom words stored in the memory 20. For instance, if the language stored in the memory 20 is, for example, English, generally each word object 108 would represent a word in the English language or would represent a custom word.

[0034] Associated with substantially each word object 108 is a frequency object 104 having frequency value that is indicative of the relative frequency within the relevant language of the given word represented by the word object 108. In this regard, the generic word list 88 includes a plurality of word objects 108 and associated frequency objects 104 that together are representative of a wide variety of words and their relative frequency within a given vernacular of, for instance, a given language. The generic word list 88 can be derived in any of a wide variety of fashions, such as by analyzing numerous texts and other language sources to determine the various words within the language sources as well as their relative probabilities, i.e., relative frequencies, of occurrences of the various words within the language sources.

[0035] The N-gram objects 112 stored within the generic word list 88 are short strings of characters within the relevant language typically, for example, one to three characters in length, and typically represent word fragments within the relevant language, although certain of the N-gram objects 112 additionally can themselves be words. However, to the extent that an N-gram object 112 also is a word within the relevant language, the same word likely would be separately stored as a word object 108 within the generic word list 88. As employed herein, the expression “string” and variations thereof shall refer broadly to an object having one or more characters or components, and can refer to any of a complete word, a fragment of a word, a custom word or expression, and the like.

[0036] In the present exemplary embodiment of the handheld electronic device 4, the N-gram objects 112 include 1-gram objects, i.e., string objects that are one character in length, 2-gram objects, i.e., string objects that are two characters in length, and 3-gram objects, i.e., string objects that are three characters in length, all of which are collectively referred to as N-grams 112. Substantially each N-gram object 112 in the generic word list 88 is similarly associated with an associated frequency object 104 stored within the generic word list 88, but the frequency object 104 associated with a given N-gram object 112 has a frequency value that indicates the relative probability that the character string represented by the particular N-gram object 112 exists at any location within any word of the relevant language. The N-gram objects 112 and the associated frequency objects 104 are a part of the corpus of the generic word list 88 and are obtained in a fashion similar to the way in which the word object 108 and the associated frequency objects 104 are obtained, although the analysis performed in obtaining the N-gram objects 112 will be slightly different because it will involve analysis of the various character strings within the various words instead of relying primarily on the relative occurrence of a given word.

[0037] The present exemplary embodiment of the handheld electronic device 4, with its exemplary language being the English language, includes twenty-six 1-gram N-gram objects 112, i.e., one 1-gram object for each of the twenty-six letters in the Latin alphabet upon which the English language is based, and further includes 676 2-gram N-gram objects 112, i.e., twenty-six squared, representing each two-letter permutation of the twenty-six letters within the Latin alphabet.

[0038] The N-gram objects 112 also include a certain quantity of 3-gram N-gram objects 112, primarily those that have a relatively high frequency within the relevant language. The exemplary embodiment of the handheld electronic device 4 includes fewer than all of the three-letter permutations of the twenty-six letters of the Latin alphabet due to considerations of data storage size, and also because the 2-gram N-gram objects 112 can already provide a meaningful amount of information regarding the relevant language. As will be set forth in greater detail below, the N-gram objects 112 and their associated frequency objects 104 provide frequency data that can be attributed to character strings for which a corresponding word object 108 cannot be identified or has not been identified, and typically is employed as a fallback data source, although this need not be exclusively the case.

[0039] In the present exemplary embodiment, the language objects 100 and the frequency objects 104 are maintained substantially inviolate in the generic word list 88, meaning that the basic language dictionary remains substantially unaltered within the generic word list 88, and the learning functions that are provided by the handheld electronic device 4 and that are described below operate in conjunction with other object that are generally stored elsewhere in memory 20, such as, for example, in the new words database 92.

[0040] The new words database 92 stores additional word objects 108 and associated frequency objects 104 in order to provide to a user a customized experience in which words and the like that are used relatively more frequently by a user will be associated with relatively higher frequency values than might otherwise be reflected in the generic word list 88. More particularly, the new words database 92 includes word objects 108 that are user-defined and that generally are not found among the word objects 108 of the generic word list 88. Each word object 108 in the new words database 92 has associated therewith an associated frequency object 104 that is also stored in the new words database 92.

[0041] The word frame table includes a plurality of word frames 51 and, associated with each word frame 51, one or more language objects 100. As will be described in greater detail below, each word frame 51 is a representation of each language object 100 that is associated therewith. The word frames 51 are advantageously configured to enable, in the event of an erroneous text input, the outputting of at least a portion of an associated language object 100 that is likely to be what the user had intended to enter but which was incorrectly entered.

[0042] FIGS. 3A, 3B, and 3C depict in an exemplary fashion the general operation of certain aspects of the disambiguation function of the handheld electronic device 4. Additional features, functions, and the like are depicted and described elsewhere.

[0043] An input is detected, as at 204, and the input can be any type of actuation or other operation as to any portion of the input apparatus 8. A typical input would include, for instance, an actuation of a key 28 having a number of characters 48 thereon, or any other type of actuation or manipulation of the input apparatus 8.

[0044] The disambiguation function then determines, as at 212, whether the current input is an operational input, such as a selection input, a delimiter input, a movement input, an alternation input, or, for instance, any other input that does not constitute an actuation of a key 28 having a number of characters 48 thereon. If the input is determined at 212 to not be an operational input, processing continues at 216 by adding the input to the current input sequence which may or may not already include an input.

[0045] Many of the inputs detected at 204 are employed in generating input sequences as to which the disambiguation function will be executed. An input sequence is built up in each “session” with each actuation of a key 28 having a number of characters 48 thereon. Since an input sequence typically will be made up of at least one actuation of a key 28 having a plurality of characters 48 thereon, the input sequence will be ambiguous. When a word, for example, is completed the current session is ended an a new session is initiated.

[0046] An input sequence is gradually built up on the handheld electronic device 4 with each successive actuation of a key 28 during any given session. Specifically, once a delimiter input is detected during any given session, the session is terminated and a new session is initiated. Each input resulting from an actuation of one of the keys 28 having a number of the characters 48 associated therewith is sequentially added to the current input sequence. As the input sequence grows during a given session, the disambiguation function generally is executed with each actuation of a key 28, i.e., input, and as to the entire input sequence. Stated otherwise, within a given session, the growing input sequence is attempted to be disambiguated as a unit by the disambiguation function with each successive actuation of the various keys 28.

[0047] Once a current input representing a most recent actuation of the one of the keys 28 having a number of the characters 48 assigned thereto has been added to the current input sequence within the current session, as at 216 in FIG. 3A, the disambiguation function generates, as at 220, substantially all of the permutations of the characters 48 assigned to the various keys 28 that were actuated in generating the input sequence. In this regard, the “permutations” refer to the various strings that can result from the characters 48 of each actuated key 28 limited by the order in which the keys 28 were actuated. The various permutations of the characters in the input sequence are employed as prefix objects.

[0048] For instance, if the current input sequence within the current session is the ambiguous input of the keys <AS> and <OP>, the various permutations of the first character 52 and the second character 56 of each of the two keys 28, when considered in the sequence in which the keys 28 were actuated, would be “SO”, “SP”, “AP”, and “AO”, and each of these is a prefix object that is generated, as at 220, with respect to the current input sequence. As will be explained in greater detail below, the disambiguation function seeks to identify for each prefix object one of the word objects 108 for which the prefix object would be a prefix.

[0049] For each generated prefix object, the memory 20 is consulted, as at 224, to identify, if possible, for each prefix object one of the word objects 108 in the memory 20 that corresponds with the prefix object, meaning that the sequence of letters represented by the prefix object would be either a prefix of the identified word object 108 or would be substantially identical to the entirety of the word object 108. Further in this regard, the word object 108 that is sought to be identified is the highest frequency word object 108. That is, the disambiguation function seeks to identify the word object 108 that corresponds with the prefix object and that also is associated with a frequency object 104 having a relatively higher frequency value than any of the other frequency objects 104 associated with the other word objects 108 that correspond with the prefix object. During this step, linguistic sources other than the word frame table 49 are consulted to identify such word objects 108.

[0050] It is noted in this regard that the word objects 108 in the generic word list 88 are generally organized in data tables that correspond with the first two letters of various words. For instance, the data table associated with the prefix “CO” would include all of the words such as “CODE”, “COIN”, “COMMUNICATION”, and the like. Depending upon the quantity of word objects 108 within any given data table, the data table may additionally include sub-data tables within which word objects 108 are organized by prefixes that are three characters or more in length. Continuing onward with the foregoing example, if the “CO” data table included, for instance, more than 256 word objects 108, the “CO” data table would additionally include one or more sub-data tables of word objects 108 corresponding with the most frequently appearing three-letter prefixes. By way of example, therefore, the “CO” data table may also include a “COM” sub-data table and a “CON” sub-data table. If a sub-data table includes more than the predetermined number of word objects 108, for example a quantity of 256, the sub-data table may include further sub-data tables, such as might be organized according to a four letter prefixes. It is noted that the aforementioned quantity of 256 of the word objects 108 corresponds with the greatest numerical value that can be stored within one byte of the memory 20.

[0051] Accordingly, when, at 224, each prefix object is sought to be used to identify a corresponding word object 108, and for instance the instant prefix object is “AP”, the “AP” data table will be consulted. Since all of the word objects 108 in the “AP” data table will correspond with the prefix object “AP”, the word object 108 in the “AP” data table with which is associated a frequency object 104 having a frequency value relatively higher than any of the other frequency objects 104 in the “AP” data table is identified. The identified word object 108 and the associated frequency object 104 are then stored in a result register that serves as a result of the various comparisons of the generated prefix objects with the contents of the memory 20.

[0052] It is noted that one or more, or possibly all, of the prefix objects will be prefix objects for which a corresponding word object 108 is not identified in the memory 20. Such prefix objects are considered to be orphan prefix objects and are separately stored or are otherwise retained for possible future use. In this regard, it is noted that many or all of the prefix objects can become orphan object if, for instance, the user is trying to enter a new word or, for example, if the user has mis-keyed and no word corresponds with the mis-keyed input.

[0053] Processing continues, as at 232, where duplicate word objects 108 associated with relatively lower frequency values are deleted from the result. Such a duplicate word object 108 could be generated, for instance, by one of the other data sources 99.

[0054] Once the duplicate word objects 108 and the associated frequency objects 104 have been removed at 232, processing continues to 236 wherein the remaining prefix objects are arranged in an output set in decreasing order of frequency value.

[0055] If it is determined, as at 240, that the flag has been set, meaning that a user has made a selection input, either through an express selection input or through an alternation input of a movement input, then the default output 76 is considered to be “locked,” meaning that the selected variant will be the default prefix until the end of the session. If it is determined at 240 that the flag has been set, the processing will proceed to 241 where the contents of the output set will be altered, if needed, to provide as the default output 76 an output that includes the selected prefix object, whether it corresponds with a word object 108 or is an artificial variant. In this regard, it is understood that the flag can be set additional times during a session, in which case the selected prefix associated with resetting of the flag thereafter becomes the “locked” default output 76 until the end of the session or until another selection input is detected.

[0056] If it was determined at 240 that the flag was not set, or alternatively after alteration of the output set has been completed at 241, processing continues at 242 where it is determined whether or not any word frame 51 corresponds with the input. As mentioned elsewhere herein, the word frames 51 are stored in the word frame table 49. The word frames 51 advantageously are configured to be recognizable by the disambiguation system 22 and, in the event of certain types of erroneous input, to enable the outputting of at least a portion of a language object 100 as a proposed corrected text input.

[0057] The exemplary word frame table 49 is depicted in greater detail in FIG. 9. The language objects 100 that are depicted as being stored therein can be stored as duplicate entries of language objects 100 stored elsewhere in the memory 20. Alternatively, the language objects 100 depicted in FIG. 9 could actually each be in the form of a pointer to another location in the memory 20, such as to a location in the generic word list 88, the new words database 92, and/or one or more of the other data sources 99, where a language object 100 is stored.

[0058] The word frames 51 are configured to be employed, as one example, in a situation of an intended input by a user of a text item such as a word which, if input correctly, would require a sequential plurality of actuations of the same key. Such a situation would occur, for instance, if the user was attempting to enter the word “connect”, wherein correct entry of the word would require a plurality of actuations of the key to which the character “N” is assigned in order to enter the “nn” portion of “connect”. In the context of the exemplary reduced keyboard of the handheld electronic device 4, a similar situation would occur if the user was attempting to enter the word “regret”, wherein the characters 48 “E” and “R” are each assigned to the same key 28, i.e., to the <ER> key 28.

[0059] Such words, in the context of the particular layouts of the characters 48 of the keypads 24 on which the words are being entered, are prone to erroneous entry due to, in accordance with the instant example, a correct entry thereof requiring a sequential plurality of actuations of the same key. For instance, if two sequential actuations of a particular key are required to correctly enter a word, it is possible that the user may erroneously actuate the particular key only one time, or the user may erroneously actuate the particular key three or more times. In either event, the output on the display 60 is erroneous. In the situation of a reduced keyboard, such as the keypad 24, a mis-keying can result in an output that bears little if any resemblance to the text that was desired to be input by the user. The improved method and device 4 of the disclosed and claimed concept can also be employed in a situation where a user intends to enter a certain key sequence and mistakenly actuates a key 28 of the input a plurality of times when the key 28 should have only been actuated once, and the incorrect input itself corresponds with a language object 100 in the memory 20.

[0060] Advantageously, therefore, each language object 100 that comprises a sequential plurality of linguistic elements that are each assigned to the same key 28 of the keypad 24 is associated with a particular word frame 51. The particular word frame 51 is configured to be representative of the associated language object 100. Specifically, the word frame 51 is configured to comprise a contracted portion 55 that is representative of the aforementioned sequential plurality of linguistic elements of the language object 100 that are each assigned to the same key 28. For example, and as is depicted generally in FIG. 9, the language object 100 corresponding with the word “connect” would be associated with a word frame 51 that comprises as a contracted portion 55 thereof a representation of a single actuation of the <BN> key 28. The contracted portion 55 would be representative of any sequential quantity of the linguistic elements assigned to the <BN> key 28, i.e., would correspond with any sequential quantity of actuations of the <BN> key 28.

[0061] The word frame 51 may additionally include a root portion 57 that is representative of the linguistic elements of the associated language object 100 that are not part of a sequential plurality of linguistic elements that are each assigned to one key 28. In the instant example, therefore, the word frame 51 that has associated therewith the language object 100 “connect” could be characterized as “CO<BN>ECT”, with the contracted portion 55 being the aforementioned <BN>, and with the root portion 57 comprising the characters “CO” preceding the contracted portion 55 and further comprising the characters “ECT” succeeding the contracted portion 55. The exemplary root portion 57 is depicted as a number of characters 48, and the contracted portion 55 is depicted as a key 28. It is noted, however, that the exemplary representation depicted herein is not intended to be limiting, and it is noted that the contracted portion 55, as well as the root portion 57, could be stored or characterized as, for example, keystrokes, characters, metaphones, etc., without limitation.

[0062] The word frames 51 are, for the most part, derived in advance from the generic word list 88. That is, the language objects 100 in the generic word list 88 are analyzed to identify those language objects 100 which would be typed by actuating a given key 28 a sequential plurality of times. As a result, the contents of the word frame table 49 are highly dependent upon the layout of the characters 48 on the various keys 28 of the keypad 24. Upon identification of such a language object 100, and if a corresponding word frame 51 that corresponds with the identified language object 100 has not already been constructed, a word frame 51 is constructed, and the identified language object 100 is associated therewith.

[0063] After all of the needed word frames 51 have been created, the generic word list 88 may again be analyzed to identify any word objects 100 which correspond with a word frame 51 that but are not already associated therewith. In this regard, it can be seen from FIG. 9 that a plurality of language objects 100, i.e., those for the words “cat” and “cast”, are associated with the word frame 51 “C<AS>T”, with “<AS>” referring to one or more actuations of the <AS> key 28.

[0064] Such entries in the word frame table 49 likely would have been generated by first identifying the language object 100 for the word “cast”, for instance, which is typed from a series of keystrokes comprising two sequential actuations of the <AS> key 28, and with construction of the corresponding word frame 51 “C<AS>T”. The language object 100 for the word “cast” would then be stored in the word frame table 49 as being associated with the word frame 51 “C<AS>T”, or would otherwise be associated therewith. The generic word list 88 would then have been re-analyzed, for instance, which would have resulted in identification of the language object 100 for the word “cat” as corresponding with the word frame 51 “C<AS>T”. The language object 100 for the word “cat” would then be stored in the word frame table 49 as being associated with the word frame 51 “C<AS>T”, or would otherwise be associated therewith.

[0065] In this regard, the language object 100 for the word “cat” would have been identified as corresponding with the word frame 51 “C<AS>T”, even though it can be seen that typing of the word “cat” does not require a sequential plurality of strokes of a given key 28, such as the <AS> key 28. However, it is anticipated that a user intending to type the word “cat” might accidentally actuate the <AS> key 28 twice instead of actuating it only once, such as by inputting <CV><AS><AS><TY>, which ordinarily would result in outputting of the words “cast” and “vast”. The method and device 4 in accordance with the disclosed and claimed concept advantageously will, as set forth in greater detail below, additionally output “cat” as a proposed disambiguation of the input.

[0066] It is noted, however, that additional word frames 51 can be learned and added to the word frame table 49. For instance, a new language object 100 is entered on the handheld electronic device 4 may additionally be analyzed to determine whether it is typed using a key sequence that comprises a sequential plurality of actuations of the same key 28. If so, it is determined whether or not the new language object 100 corresponds with a word frame 51 already in existence. If such a word frame 51 already exists, the new language object 100 is added to the word frame table 49 or is otherwise associated with the word frame 51.

[0067] On the other hand, if no corresponding word frame 51 already exists, a new word frame 51 is created, and the new language object 100 is added to the word frame table 49 or is otherwise associated with the new word frame 51. Additionally, the generic word list 88 and any other linguistic sources may be analyzed to determine whether or not any other language object 100 corresponds with the new word frame 51. Any such other language object 100 that is identified is added to the word frame table 49 or is otherwise associated with the new word frame 51.

[0068] New language objects 100 can be entered on the handheld electronic device 4 in any of a variety of ways. For instance, a new language object 100 can be entered on the handheld electronic device 4 as an input comprising a number of key actuations. A new language object 100 could also be entered on the handheld electronic device 4 as a result of being received on the handheld electronic device 4. For instance, the handheld electronic device 4 can receive new language objects 100 via receipt of electronic mail or via operation of other messaging routines. Moreover, new language objects 100 can be received on the handheld electronic device 4 as a result of installation of new applications or routines. New language objects 100 can be received or otherwise entered on the handheld electronic device 4 in other ways as well.

[0069] During text entry, and as mentioned above, the disambiguation routine generates prefixes, as at 220, and seeks language objects 100, as at 224. All such identified language objects 100 will correspond directly with the input. However, in order to provide proposed corrected output in the event of a mis-keying of a sequential plurality of actuations of the same key, the input is compared, as at 242 in FIG. 3C, with the word frames 51 in the word frame table 49. Specifically, the input is compared with each of a number of the word frames 51 to determine if any word frame 51 corresponds with the input. For instance, if the input was an ambiguous input of actuations of the keys 28 <CV><OP><BN><ER>, it would be determined whether or not the input comprised one or more sequential actuations of, in the present example, the <BN> key 28. It would also be determined whether or not another portion of the input corresponded with at least some of the linguistic elements of the root portion 57 of the same word frame 51. In the example of the word frame 51 “CO<BN>ECT” and the exemplary input <CV><OP><BN><ER>, it would be determined whether or not the input comprised key actuations which preceded and followed the actuation(s) of the <BN> key 28 and that corresponded with, for example, the characters 48 “C”, “ ”, and “E” of the root portion 57.

[0070] In the present example, an input comprising actuations of the keys 28 <CV><OP><BN><ER> would cause the word frame 51 “CO<BN>ECT” to be identified in the affirmative at 242. This is because the first two key actuations <CV><OP> would correspond with the tow sequential linguistic elements “C” and “O” of the root portion 57 that precede the contracted portion 55, the actuation of the <BN> key 28 would correspond with the contracted portion 55, and the actuation of the <ER> key 28 would correspond with the character “E” of the root portion 57 that immediately follows the contracted portion 55.

[0071] Processing thereafter would proceed to 243 where it would be determined whether or not each language object 100 which corresponds with the identified word frame 51 is included in the output set which was generated at 236 and 241. In the present example, the language object 100 “connect” is associated with the word frame 51 “CO<BN>ECT”. If it is determined that the language object 100 “connect” is not reflected in the output set, and based upon the method set forth above at the elements 220 and 224 it can be assumed that the input <CV><OP><BN><ER> would not result in identification of the language object 100 “connect” in any of the generic word list 88, the new words database 92, and the other data sources 99, the language object 100 “connect” would, at 244, be added at least in part to the output set.

[0072] Processing would thereafter proceed to 245 where at least a portion of the output set would be output, for instance, on the display 60. Processing would thereafter proceed, as at 246, to the numeral 204 in FIG. 3A.

[0073] On the other hand, if it is determined at 243 that the language object 100 that is associated with the identified word frame 51 is, in fact, already included in the output set, processing would proceed directly to 245 where at least a portion of the output set would be output without adding the additional language object 100. Processing would thereafter proceed, as at 246, to the numeral 204 in FIG. 3A. This would be the situation if, for example, the input was <CV><OP><BN><BN><ER>. Such as input would result in the language object 100 “connect” being identified at 224 in the generic word list 88 and being included in the output set. However, if the desired input “connect” was mis-keyed as <CV><OP><BN><ER> as in the present mis-keying example, the language object 100 “connect” would not have been identified at 224 in the generic word list 88, but advantageously would have been added to the output set at 244 as a result of the word frame 51 “CO<BN>ECT” being identified at 242 as corresponding with the mis-keyed input. Advantageously, therefore, the improved method of FIG. 3C enables outputting of certain words which the user may have intended to type but which were mis-keyed by the user.

[0074] If it is determined at 242 that no word frame 51 corresponds with the input, it is then determined, as at 247, whether any word frames 51 have a root portion 57 that is within an edit distance equal to a value of one with respect to a similar portion of the input. In this regard, an edit distance of one between a portion of the input and a root portion 57 would exist, for instance, in any of the following situations: i) all but one of the key actuations of that portion of the input correspond with similar portions of the root portion 57, with one of the key actuations not corresponding with one of the linguistic elements of the root portion 57; ii) all of the key actuations of that portion of the input correspond with similar portions of the root portion 57, but the root portion 57 has one linguistic element more than that portion of the input; and iii) the root portion 57 corresponds with similar portions of the input, but the input has one linguistic element more than that part of the root portion 57.

[0075] If one of these three situations occurred in conjunction with correspondence between the input and the contracted portion 55 of the word frame 51, there would be a partial correspondence between the input and the identified word frame 51, i.e., correspondence within an edit distance of one. In the event of such partial correspondence, processing would continue, as at 248, where it would be determined whether the searching at 224 identified any language objects 110. If language objects 110 were identified at 224, processing would, in the present exemplary embodiment, continue to 245 where the output set would be output at least in part without the addition thereto of a language object that was associated with the at least partially corresponding word frame 51 identified at 247.

[0076] On the other hand, if it is determined at 248 that no language objects 100 were identified at 224, processing would continue at 244 where the language objects 100 associated with the word frame 51 identified at 247 would be added to the output set. Processing would thereafter proceed to 245 where at least a portion of the output set would be output, and thereafter processing would proceed, as at 246, to the numeral 204 in FIG. 3A.

[0077] In the present example of the input <CV><OP><BN><ER>, the disambiguation system would have identified at 224 the language object 100 for the word “cone”. Additionally, the system would at 244 add to the output set at least a portion of the language object 100 “connect”. The output on the display 60 in response to such an input would comprise “cone” as the default portion 76 and “conne” as the variant portion 80. That is, the output “conne” would comprise one character more than the number of key actuations of the input. Some additional examples of mis-keyed attempts to enter “connect” are presented below.

[0078] If the input was <CV><OP><BN><BN><BN><ER>, the system would again at 244 add to the output set at least a portion of the language object 100 “connect”. In response to such an input, the output on the display 60 would comprise “conne” as the default portion 76. That is, the output “conne” would comprise one character fewer than the number of key actuations of the input. It is noted that in this example and in the example of the preceding paragraph, the input corresponded with both the contracted portion 55 and the root portion 57 of the word frame “CO<BN>ECT”.

[0079] If the input was <CV><BN>, the disambiguation system might have identified at 224 the language object 100 for the word “cnidoblast” and thus would output “cn” as the default portion 76. If the next keystroke of the input is <BN>, thus making the current input <CV><BN><BN>, no corresponding language object 100 would have been identified at 224. Moreover, no word frame 51 would have been identified at 242. However, at 247 the word frame 51 “CO<BN>ECT” would be identified as being within an edit distance of one to the input. That is, the <BN><BN> portion of the input would correspond with the contracted portion 55, and the <CV> portion of the input would meet situation ii) above, i.e., the key actuation <CV> corresponds with the character “C” of the root portion 57, but the root portion 57 additionally has the character “O”, which is one linguistic element more than that portion of the input. This meets the requirement of partial correspondence at 247. Since the input <CV><BN><BN> would not result in identification at 224 of any language object 100, the language object 100 “connect”, which is associated with the word frame 51 “CO<BN>ECT” identified at 247, would be added at 244 to the output set, and at 245 “conn” would be output as the default portion 76. The output again would have one character more than the input, but this time would be a result of only partial correspondence between the input and the word frame 51.

[0080] If the input was <CV><TY><BN><BN>, no language object 100 would be identified at 224. Moreover, no word frame 51 would have been identified at 242. However, at 247 the word frame 51 “CO<BN>ECT” would be identified as being within an edit distance of one to the input. That is, the <BN><BN> portion of the input would correspond with the contracted portion 55, and the <CV><TY> portion of the input would meet situation i) above, i.e., the key actuation <CV> corresponds with the character “C” of the root portion 57, but <TY> does not correspond with the character “O” of the root portion 57. This meets the requirement of partial correspondence at 247. Since the input <CV><TY><BN><BN> would not result in identification at 224 of any language object 100, the language object 100 “connect”, which is associated with the word frame 51 “CO<BN>ECT” identified at 247, would be added at 244 to the output set, and at 245 “conn” would be output as the default portion 76.

[0081] It will be apparent that certain word frames 51 can have multiple contracted portions 55, such as the way in which the word frame 51 B<OP><JK><ER>P<ER>, which corresponds with the language object 100 “bookkeeper”, has four contracted portions 55. Correspondence with such a word frame 51 can occur in a fashion that will be apparent in view of the foregoing. It is further noted that the root portion 57 of certain word frames 51 can be split into multiple parts and can exist, for instance, between multiple contracted portions 55, again such as with the word frame 51 B<OP><JK><ER>P<ER>. Again, correspondence with such a word frame 51 can occur in a fashion that will be apparent in view of the foregoing.

[0082] If the detected input is determined, as at 212, to be an operational input, processing then continues to determine the specific nature of the operational input. For instance, if it is determined, as at 252, that the current input is a selection input, processing continues at 254 where the flag is set. Processing then returns to detection of additional inputs as at 204.

[0083] If it is determined, as at 260, that the input is a delimiter input, processing continues at 264 where the current session is terminated and processing is transferred, as at 266, to the learning function subsystem, as at 404 of FIG. 4. A delimiter input would include, for example, the actuation of a <SPACE> key 116, which would both enter a delimiter symbol and would add a space at the end of the word, actuation of the <ENTER> key, which might similarly enter a delimiter input and enter a space, and by a translation of the thumbwheel 32, such as is indicated by the arrow 38, which might enter a delimiter input without additionally entering a space.

[0084] It is first determined, as at 408, whether the default output at the time of the detection of the delimiter input at 260 matches a word object 108 in the memory 20. If it does not, this means that the default output is a user-created output that should be added to the new words database 92 for future use. In such a circumstance processing then proceeds to 412 where the default output is stored in the new words database 92 as a new word object 108. Additionally, a frequency object 104 is stored in the new words database 92 and is associated with the aforementioned new word object 108. The new frequency object 104 is given a relatively high frequency value, typically within the upper one-fourth or one-third of a predetermined range of possible frequency values.

[0085] In this regard, frequency objects 104 are given an absolute frequency value generally in the range of zero to 65,535. The maximum value represents the largest number that can be stored within two bytes of the memory 20. The new frequency object 104 that is stored in the new words database 92 is assigned an absolute frequency value within the upper one-fourth or one-third of this range, particularly since the new word was used by a user and is likely to be used again.

[0086] With further regard to frequency object 104, it is noted that within a given data table, such as the “CO” data table mentioned above, the absolute frequency value is stored only for the frequency object 104 having the highest frequency value within the data table. All of the other frequency objects 104 in the same data table have frequency values stored as percentage values normalized to the aforementioned maximum absolute frequency value. That is, after identification of the frequency object 104 having the highest frequency value within a given data table, all of the other frequency objects 104 in the same data table are assigned a percentage of the absolute maximum value, which represents the ratio of the relatively smaller absolute frequency value of a particular frequency object 104 to the absolute frequency value of the aforementioned highest value frequency object 104. Advantageously, such percentage values can be stored within a single byte of memory, thus saving storage space within the handheld electronic device 4.

[0087] Upon creation of the new word object 108 and the new frequency object 104, and storage thereof within the new words database 92, processing is transferred to 420 where the learning process is terminated. Processing is then returned to the main process, as at 204. If at 408 it is determined that the word object 108 in the default output 76 matches a word object 108 within the memory 20, processing is returned directly to the main process at 204.

[0088] With further regard to the identification of various word objects 108 for correspondence with generated prefix objects, it is noted that the memory 20 can include a number of other data sources 99 in addition to the generic word list 88, the new words database 92, and the word frame table, all of which can be considered linguistic sources. It is understood that the memory 20 might include any number of other data sources 99. The other data sources 99 might include, for example, an address database, a speed-text database, or any other data source without limitation. An exemplary speed-text database might include, for example, sets of words or expressions or other data that are each associated with, for example, a character string that may be abbreviated. For example, a speed-text database might associate the string “br” with the set of words “Best Regards”, with the intention that a user can type the string “br” and receive the output “Best Regards”.

[0089] In seeking to identify word objects 108 that correspond with a given prefix object, the handheld electronic device 4 may poll all of the data sources in the memory 20. For instance the handheld electronic device 4 may poll the generic word list 88, the new words database 92, and the other data sources 99 to identify word objects 108 that correspond with the prefix object. The contents of the other data sources 99 may be treated as word objects 108, and the processor 16 may generate frequency objects 104 that will be associated with such word objects 108 and to which may be assigned a frequency value in, for example, the upper one-third or one-fourth of the aforementioned frequency range. Assuming that the assigned frequency value is sufficiently high, the string “br”, for example, would typically be output to the display 60. If a delimiter input is detected with respect to the portion of the output having the association with the word object 108 in the speed-text database, for instance “br”, the user would receive the output “Best Regards”, it being understood that the user might also have entered a selection input as to the exemplary string “br”.

[0090] The contents of any of the other data sources 99 may be treated as word objects 108 and may be associated with generated frequency objects 104 having the assigned frequency value in the aforementioned upper portion of the frequency range. After such word objects 108 are identified, the new word learning function can, if appropriate, act upon such word objects 108 in the fashion set forth above.

[0091] If it is determined, such as at 268, that the current input is a movement input, such as would be employed when a user is seeking to edit an object, either a completed word or a prefix object within the current session, the caret 84 is moved, as at 272, to the desired location, and the flag is set, as at 276. Processing then returns to where additional inputs can be detected, as at 204.

[0092] In this regard, it is understood that various types of movement inputs can be detected from the input device 8. For instance, a rotation of the thumbwheel 32, such as is indicated by the arrow 34 of FIG. 1, could provide a movement input. In the instance where such a movement input is detected, such as in the circumstance of an editing input, the movement input is additionally detected as a selection input. Accordingly, and as is the case with a selection input such as is detected at 252, the selected variant is effectively locked with respect to the default portion 76 of the output 64. Any default output 76 during the same session will necessarily include the previously selected variant.

[0093] In the present exemplary embodiment of the handheld electronic device 4, if it is determined, as at 252, that the input is not a selection input, and it is determined, as at 260, that the input is not a delimiter input, and it is further determined, as at 268, that the input is not a movement input, in the current exemplary embodiment of the handheld electronic device 4 the only remaining operational input generally is a detection of the <DELETE> key 86 of the keys 28 of the keypad 24. Upon detection of the <DELETE> key 86, the final character of the default output is deleted, as at 280. Processing thereafter returns to 204 where additional input can be detected.

[0094] An exemplary input sequence is depicted in FIGS. 1 and 5-8. In this example, the user is attempting to enter the word “APPLOADER”, and this word presently is not stored in the memory 20. In FIG. 1 the user has already typed the “AS” key 28. Since the data tables in the memory 20 are organized according to two-letter prefixes, the contents of the output 64 upon the first keystroke are obtained from the N-gram objects 112 within the memory. The first keystroke “AS” corresponds with a first N-gram object 112 “S” and an associated frequency object 104, as well as another N-gram object 112 “A” and an associated frequency object 104. While the frequency object 104 associated with “S” has a frequency value greater than that of the frequency object 104 associated with “A”, it is noted that “A” is itself a complete word. A complete word is always provided as the default output 76 in favor of other prefix objects that do not match complete words, regardless of associated frequency value. As such, in FIG. 1, the default portion 76 of the output 64 is “A”.

[0095] In FIG. 5, the user has additionally entered the “OP” key 28. The variants are depicted in FIG. 5. Since the prefix object “SO” is also a word, it is provided as the default output 76. In FIG. 6, the user has again entered the “OP” key 28 and has also entered the “L” key 28. It is noted that the exemplary “L” key 28 depicted herein includes only the single character 48 “L”.

[0096] It is assumed in the instant example that no operational inputs have thus far been detected. The default output 76 is “APPL”, such as would correspond with the word “APPLE”. The prefix “APPL” is depicted both in the text component 68, as well as in the default portion 76 of the variant component 72. Variant prefix objects in the variant portion 80 include “APOL”, such as would correspond with the word “APOLOGIZE”, and the prefix “SPOL”, such as would correspond with the word “SPOLIATION”.

[0097] It is particularly noted that the additional variants “AOOL”, “AOPL”, “SOPL”, and “SOOL” are also depicted as variants 80 in the variant component 72. Since no word object 108 corresponds with these prefix objects, the prefix objects are considered to be orphan prefix objects for which a corresponding word object 108 was not identified. In this regard, it may be desirable for the variant component 72 to include a specific quantity of entries, and in the case of the instant exemplary embodiment the quantity is seven entries. Upon obtaining the result at 224, if the quantity of prefix objects in the result is fewer than the predetermined quantity, the disambiguation function will seek to provide additional outputs until the predetermined number of outputs are provided.

[0098] In FIG. 7 the user has additionally entered the “OP” key 28. In this circumstance, and as can be seen in FIG. 7, the default portion 76 of the output 64 has become the prefix object “APOLO” such as would correspond with the word “APOLOGIZE”, whereas immediately prior to the current input the default portion 76 of the output 64 of FIG. 6 was “APPL” such as would correspond with the word “APPLE.” Again, assuming that no operational inputs had been detected, the default prefix object in FIG. 7 does not correspond with the previous default prefix object of FIG. 6. As such, a first artificial variant “APOLP” is generated and in the current example is given a preferred position. The aforementioned artificial variant “APOLP” is generated by deleting the final character of the default prefix object “APOLO” and by supplying in its place an opposite character 48 of the key 28 which generated the final character of the default portion 76 of the output 64, which in the current example of FIG. 7 is “P”, so that the aforementioned artificial variant is “APOLP”.

[0099] Furthermore, since the previous default output “APPL” corresponded with a word object 108, such as the word object 108 corresponding with the word “APPLE”, and since with the addition of the current input the previous default output “APPL” no longer corresponds with a word object 108, two additional artificial variants are generated. One artificial variant is “APPLP” and the other artificial variant is “APPLO”, and these correspond with the previous default output “APPL” plus the characters 48 of the key 28 that was actuated to generate the current input. These artificial variants are similarly output as part of the variant portion 80 of the output 64.

[0100] As can be seen in FIG. 7, the default portion 76 of the output 64 “APOLO” no longer seems to match what would be needed as a prefix for “APPLOADER”, and the user likely anticipates that the desired word “APPLOADER” is not already stored in the memory 20. As such, the user provides a selection input, such as by scrolling with the thumbwheel 32 until the variant string “APPLO” is highlighted. The user then continues typing and enters the “AS” key.

[0101] The output 64 of such action is depicted in FIG. 8. Here, the string “APPLOA” is the default portion 76 of the output 64. Since the variant string “APPLO” became the default portion 76 of the output 64 (not expressly depicted herein) as a result of the selection input as to the variant string “APPLO”, and since the variant string “APPLO” does not correspond with a word object 108, the character strings “APPLOA” and “APPLOS” were created as an artificial variants. Additionally, since the previous default of FIG. 7, “APOLO” previously had corresponded with a word object 108, but now is no longer in correspondence with the default portion 76 of the output 64 of FIG. 8, the additional artificial variants of “APOLOA” and “APOLOS” were also generated. Such artificial variants are given a preferred position in favor of the three displayed orphan prefix objects.

[0102] Since the current input sequence in the example no longer corresponds with any word object 108, the portions of the method related to attempting to find corresponding word objects 108 are not executed with further inputs for the current session. That is, since no word object 108 corresponds with the current input sequence, further inputs will likewise not correspond with any word object 108. Avoiding the search of the memory 20 for such nonexistent word objects 108 saves time and avoids wasted processing effort.

[0103] As the user continues to type, the user ultimately will successfully enter the word “APPLOADER” and will enter a delimiter input. Upon detection of the delimiter input after the entry of “APPLOADER”, the learning function is initiated. Since the word “APPLOADER” does not correspond with a word object 108 in the memory 20, a new word object 108 corresponding with “APPLOADER” is generated and is stored in the new words database 92, along with a corresponding new frequency object 104 which is given an absolute frequency in the upper, say, one-third or one-fourth of the possible frequency range. In this regard, it is noted that the new words database 92 is generally organized in two-character prefix data tables similar to those found in the generic word list 88. As such, the new frequency object 104 is initially assigned an absolute frequency value, but upon storage the absolute frequency value, if it is not the maximum value within that data table, will be changed to include a normalized frequency value percentage normalized to whatever is the maximum frequency value within that data table.

[0104] It is noted that the layout of the characters 48 disposed on the keys 28 in FIG. 1 is an exemplary character layout that would be employed where the intended primary language used on the handheld electronic device 4 was, for instance, English. Other layouts involving these characters 48 and/or other characters can be used depending upon the intended primary language and any language bias in the makeup of the language objects 100.

[0105] While specific embodiments of the disclosed and claimed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed and claimed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.