Multiple predictions in a reduced keyboard disambiguating system

A computer receives user entry of a sequence of keypresses, representing an intended series of letters collectively spelling-out some or all of a desired textual object. Resolution of the intended series of letters and the desired textual object is ambiguous, however, because some or all of the key presses individually represent multiple letters. The computer interprets the keypresses utilizing concurrent, competing strategies, including one-keypress-per-letter and multi-tap interpretations. The computer displays a combined output of proposed interpretations and completions from both strategies.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to systems for resolving a user's intended entry of textual objects using a reduced keyboard, where the intended textual objects are ambiguous because some or all of the key presses individually represent multiple letters. More particularly, the invention concurrently automatically applies competing interpretation strategies including one-keypress-per-letter and a multi-tap, and presents the user with a combined output from both strategies.

2. Description of the Related Art

Handheld digital devices are becoming increasingly widespread. Some digital devices are dedicated to simpler tasks, as in the case of a television remote control. Other devices offer general purpose computing platforms, as in the case of personal data assistants (PDAs). Other devices offer a combination of these, as in the case of many mobile phones, which place and receive calls, but also perform address management, web surfing, text messaging, and other computing functions.

Although some handheld, general purpose computers offer a full keyboard, many others do not. Many mobile phones only come with a simple keypad of twelve keys. Without a full keyboard, text entry is still possible, but some shortcuts and accommodations are inevitable. Accordingly, being constrained with a reduced keyboard presents many challenges in designing user interfaces that are simple, intuitive, fast, and powerful.

SUMMARY OF THE INVENTION

A computer receives user entry of a sequence of keypresses, representing an intended series of letters collectively spelling-out some or all of a desired textual object. Resolution of the intended series of letters and the desired textual object is ambiguous, however, because some or all of the key presses individually represent multiple letters. The computer interprets the keypresses utilizing concurrent, competing strategies, including one-keypress-per-letter and multi-tap interpretations. The computer displays a combined output of proposed interpretations and completions from both strategies.

The teachings of this disclosure may be implemented as a method, apparatus, logic circuit, storage medium, or a combination of these. This disclosure provides a number of other advantages and benefits, which should be apparent from the following description.

DETAILED DESCRIPTION

The nature, objectives, and advantages of the invention will become more apparent to those skilled in the art after considering the following detailed description in connection with the accompanying drawings.

Hardware Components & Interconnections

Introduction

One aspect of the present disclosure concerns a handheld digital device, as exemplified by device100ofFIG. 1A. The device100may be implemented in different forms, such as a cell phone, satellite phone, wireless radio, PDA, GPS, etc.

Display

The device100includes a display102to visibly present human readable information to the user. In one example, the display102comprises a relatively small LCD display of a mobile phone. However, the display102may be implemented by another size or configuration of LCD display, CRT, OLED or plasma display, laser or holographic output, or any other device for receiving a machine-readable input signal and providing a human-readable output.

As shown inFIG. 1B, the display102in this example includes various panes152-156. These include a text pane152, which displays words that have been entered and confirmed by the user (such as158). Optionally, the text pane152may show a default interpretation (not shown) of the current key sequence, where this interpretation is not yet confirmed. The default interpretation, if this option is used, may begin at a text insertion point157. The keypress buffer sequence pane156lists the key presses being interpreted. It may also serve as the numeric interpretation of the current key sequence, permitting entry of arbitrary digit sequences without changing to a numeric mode. Optionally, the pane156may be hidden, but its illustration persists in the drawings because it is helpful to explain the operation of the other panes.

The single-keypress-per-letter (SKPL) pane153presents SKPL interpretation of the keypresses156. The multi-tap pane154presents a multi-tap interpretation of the keypresses156. The SKPL and multi-tap methodologies are discussed in greater detail below. The completions pane155contains entries from the vocabulary124(discussed below) that meet the following criteria: a character sequence in the panes153or154forms the beginning (or entirety) of the vocabulary entry. Word completion refers to the act of proposing a full word (or phrase) that completes the word prefix entered so far, and may also be referred to herein as word prediction.

In other embodiments, the arrangement of panes may vary. For example, the interpretations/panes153-156may form a segmented vertical list floating over the text pane152, with the multi-tap or numeric interpretation at the top, SKPL interpretations in the middle, and completions at the bottom of the list. Many other arrangements are possible.

Keypad

Referring toFIG. 1A, the keypad104comprises any input device with a plurality of defined switches, locations, keys, soft keys, or other feature associated with input “letters” (defined broadly). These will be referred to as “keys.” Some examples of a keypad include a touch sensitive screen having defined areas for keys; discrete mechanical or membrane keys; virtual keyboards, which shall include by way of example, but not limitation, virtual-reality keyboards, laser-projection keyboards, muscle-sensing keyboards, and fabric keyboards; on-screen keyboard for a personal computer, media player, or game console. This disclosure provides some examples of the type and number of keys below in the discussion of key maps122, below.

In addition to the keypad104, the device100may include other user input tools, such as joystick, rocker, handwriting digitizing surface, mouse, roller ball stylus, track ball, mouse, pointing stick, combination of these, or other mechanism appropriate to the application at hand.

Processor

In addition to performing various computations concerning the operation of the device100, the processor106manages the display102, receives and interprets input from the keypad104, and reads/writes data to/from storage108. The processor106may be coupled to other components107, depending on how the device100is implemented. Some examples of these components107include a transmitter, receiver, microphone, speaker, input/output ports, charging circuitry, etc.

In one example, the processor106is a digital data processing entity such as those used in PDAs. However, in a more general sense, the function of the processor106may be implemented by one or more hardware devices, software devices, a portion of one or more hardware or software devices, or a combination of these. The makeup of these subcomponents is described in greater detail below, with reference toFIGS. 2-4.

Storage

Broadly, the storage108serves to store digital data for on-demand access by the processor106. In one example, the storage108comprises micro-sized flash memory of the type used in compact applications such as PDAs. However, the storage108may be implemented by a variety of hardware, as discussed in detail below with reference toFIGS. 3-4. As to data structure for storage subcomponent components120,122, and124, these may be implemented by linked lists, lookup tables, relational databases, registers, or other useful data structure. As to the code126(discussed below), the data structure for this component may include compiled code, interpreted code, source code, object oriented programming, machine instructions, or any other appropriate format.

Buffers

The storage108may include various buffers120. These may be physical structures, software, or merely conceptual constructs used herein to illustrate the operation of the system100. Among these buffers, an input buffer stores a record of keypresses and other user inputs. The input buffer preserves the user entries in the order of entry, or at least stores some record of that order. Other buffers, for example, may be provided for functions such as keeping track of the contents of the displayed panes152-156, etc.

Key maps122indicate which letters items are assigned to which keys of the keypad104. Although this disclosure makes reference to keypad entry of “letters” for the sake of convenience and without any intended limitation, these may vary according to the intended utility. Some examples include alphabetic letters, symbols, punctuation, numerals, non-alphabetic phonetic letters, and other input to the keypad keys. Still further examples include accented or unaccented letters or other characters or symbols of a written script, including those that represent a phonetic or sub-word component, including Japanese kana, Korean jamos, and Chinese zhuyin, or other linguistic and non-linguistic characters such as digits and punctuation commonly found in computer-based text. Optionally, different mappings may be used according to contexts, application program, user-selection, etc. The term “letter,” then, is used broadly in this disclosure and may include any or all of the foregoing.

An exemplary mapping appears inFIG. 1C. This mapping is appropriate for user entry of Indo-European language words, Pinyin, romaji, and some phonetic representations of logographic characters. Other mappings may be applied as appropriate for other non-Latin scripts such as Hindi and other languages, dialects, etc.

As demonstrated byFIG. 1C, the map122produces inherently ambiguous results when the user enters keypresses to signify alphabetic letters, since multiple letters are always assigned to the same key. Namely, user-entered key presses are inherently ambiguous in that the key sequence could represent different combinations of intended letters, depending upon which letter interpretation was intended for each key press.

In order to identify key presses unambiguously in this disclosure, shorthand reference is made to the numeral on the key. For instance, a “2” key is shorthand for the key ofFIG. 1Cdepicting “2” and “ABC,” even though the numeral itself might be irrelevant to the discussion.

Vocabulary

A vocabulary124contains a listing of textual objects that are recognized by the system100. A textual object is a linguistic object, such as a string of one or more letters, characters, or symbols of a written script forming a word, name, word stem, prefix or suffix, phrase, abbreviation, chat slang, emoticon, user ID, URL, recognized phonetic spelling of a logographic character or character phrase or character component, etc. Each textual object listed in the vocabulary is an “entry” of the vocabulary. Entries in the vocabulary124may also be referred to as “valid entries” or “recognized entries” to emphasize the fact that user-entered text is being evaluated against the established vocabulary. Without any intended limitation, this disclosure utilizes “word” as shorthand for textual object, for ease of reading.

The system100may include one vocabulary124(as illustrated) or multiple vocabularies. One example of a vocabulary is “American English words.” Another example vocabulary example is “German words.” Another example of a vocabulary is Pinyin spellings of Chinese characters. The system may use separate vocabularies in separate applications, or it may use all vocabularies concurrently. For ease of explanation, however, the present discussion assumes a single installed vocabulary, and more particularly, a vocabulary of American English words. In any case, the entries in the vocabulary be taken or derived from various known standards, extracted from corpus, supplemented based on actual use, etc.

The vocabulary124may be fixed at manufacture of the system100, or downloaded upon installation or boot-up or reconfiguration or another suitable time. The vocabulary124may self-update to gather new phrases from time to time, by consulting users' previous input, the Internet, wireless network, or another source.

The vocabulary124, explained as a sequence of text objects, is useful for ease of explanation. However, the vocabulary124may not even contain words or letters at all, and instead it may contain key sequences to save time in interpreting key sequences and then cross-referencing the vocabulary. In this respect, the vocabulary124may be implemented by one or more trees, run-length-encoded table structures, or other optimized data.

Code126represents machine readable instructions for execution by the processor106. Thus, the code126may provide the processor106with some or all of its functionality. Some further details of the code126are explained below in conjunction withFIGS. 2-4. As will be seen, the code126may be omitted entirely in cases where the processor106favors logic circuitry or other alternatives over machine-executable instructions.

Exemplary Digital Data Processing Apparatus

As mentioned above, data processing entities (such as the processor106) may be implemented in various forms.

Some examples include a general purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

As a more specific example,FIG. 2shows a digital data processing apparatus200. The apparatus200includes a processor202, such as a microprocessor, personal computer, workstation, controller, microcontroller, state machine, or other processing machine, coupled to a digital data storage204. In the present example, the storage204includes a fast-access storage206, as well as nonvolatile storage208. The fast-access storage206may be used, for example, to store the programming instructions executed by the processor202. The storage206and208may be implemented by various devices, such as those discussed in greater detail in conjunction withFIGS. 3 and 4. Many alternatives are possible. For instance, one of the components206,208may be eliminated; furthermore, the storage204,206, and/or208may be provided on-board the processor202, or even provided externally to the apparatus200.

The apparatus200also includes an input/output210, such as a connector, line, bus, cable, buffer, electromagnetic link, network, modem, transducer, IR port, antenna, or other means for the processor202to exchange data with other hardware external to the apparatus200.

Storage Media

As mentioned above, various instances of digital data storage may be used, for example, to provide storage used by the system100(FIG. 1), to embody the storage204and208(FIG. 2), etc. Depending upon its application, this digital data storage may be used for various functions, such as storing data, or to store machine-readable instructions. These instructions may themselves aid in carrying out various processing functions, or they may serve to install a software program upon a computer, where such software program is then executable to perform other functions related to this disclosure.

In any case, the storage media may be implemented by nearly any mechanism to digitally store machine-readable signals. One example is optical storage such as CD-ROM, WORM, DVD, digital optical tape, disk storage300(FIG. 3), or other optical storage. Another example is direct access storage, such as a conventional “hard drive”, redundant array of inexpensive disks (“RAID”), or another direct access storage device (“DASD”). Another example is serial-access storage such as magnetic or optical tape. Still other examples of digital data storage include electronic memory such as ROM, EPROM, flash PROM, EEPROM, memory registers, battery backed-up RAM, etc.

An exemplary storage medium is coupled to a processor so the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. In another example, the processor and the storage medium may reside in an ASIC or other integrated circuit.

Logic Circuitry

In contrast to storage media that contain machine-executable instructions (as described above), a different embodiment uses logic circuitry to implement data processing entities such as the processor106.

Depending upon the particular requirements of the application in the areas of speed, expense, tooling costs, and the like, this logic may be implemented by constructing an application-specific integrated circuit (ASIC) having thousands of tiny integrated transistors. Such an ASIC may be implemented with CMOS, TTL, VLSI, or another suitable construction. Other alternatives include a digital signal processing chip (DSP), discrete circuitry (such as resistors, capacitors, diodes, inductors, and transistors), field programmable gate array (FPGA), programmable logic array (PLA), programmable logic device (PLD), and the like.

FIG. 4shows an example of logic circuitry in the form of an integrated circuit400.

OPERATION

Having described the structural features of the present disclosure, the operational aspect of the disclosure will now be described. The steps of any method, process, or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by hardware, or in a combination of the two.

Terminology

This disclosure refers to the SKPL technology and multi-tap disambiguation strategies. Broadly, SKPL concerns single-key-per-letter technology, including word-based and phrase-based disambiguation methods, and may also be referred to as predictive text. Multi-tap refers to multiple-key-per-letter technology. For general reference, some are other letter-based disambiguation methods include as two-key input (including chording) and select-and-scroll.

SKPL assumes that each keypress represents a single user-intended letter (or numeral or symbol, etc.). Since various keys represent multiple letters, the device100considers all of the possibilities for each keypress to formulate the text string spelled out by the user's keypresses the device100. Therefore, after each keypress, the system considers the various possible combinations by taking one letter from this key press, and one letter from each key press previously entered. Although theoretically possible, generating all combinations of letter sequences becomes impractical after just a few keys. Therefore, certain known shortcuts are taken to limit the potential combinations.

The system100examines the vocabulary124to determine whether the current key sequence corresponds to any complete words in the vocabulary124, or whether the current key sequence forms the stem (beginning one or more letters) of any words in the vocabulary124. A stem may refer to a prefix, root word, or component of a textual object. The device100presents some or all of these to the user. Optionally, the device may order the found words based on recency of use, context, frequency of use by the user or general population or other group, and/or other factors.

Certain instances of SKPL technology are available in a number of commercially available products under the trademark “T9.” SKPL technology is additionally described in a number of patents and publications, with some examples including: U.S. Pat. Nos. 5,818,437, 6,307,549, 6,286,064, U.S. application Ser. No. 10/176,933.

In contrast to SKPL, with the multi-tap interpretation strategy, the user enters repeated keypresses to cycle through the letters assigned to a key. For instance, pressing the “8” key twice would enter the letter “U.” Pressing the “8” key three times designates the letter “V.”

The user can confirm entry of a given letter in one or all of the following ways. First, a letter is confirmed when the user presses a different key. For instance, if the user presses the “2” key three times and then begins to press the “5” key, this confirms entry of a “C” since it was the third letter on the “2” key. Second, a letter is confirmed when the user delays for a predetermined period of time after pressing a given key one or more times. For instance, if the user presses the “2” key twice, and waits (for example, less than one second), this confirms entry of a “B.” Third, a letter is confirmed when the user affirmatively enters a space or other letter delimiter, such as the right-arrow key, with the keypad or other data entry tool.

As an alternative to letter confirmation, the device100may analyze some or all of a keypress sequence as a whole. An exemplary keypress sequence is “666667777.” Here, the system may interpret the sequence as “NOS” (66-666-7777) or MOMS (6-666-6-777-7). In order to perform this type of analysis, the system considers the input sequence as a whole, and figures all possible delineations between letters. Then, having allocated keypresses to letters, the system identifies each letter by the number and identity of its allocated keypresses.

There are a number of commercially available products that employ multi-tap technology. Moreover, this technology is described in a number of U.S. patents, with some examples including Nos.: U.S. Pat. Nos. 3,675,513, 4,191,854, 4,427,848, 5,007,008, 5,392,338, 5,748,512.

Simple Example

In a broad sense, the device100aims to resolve a user's intended entry of textual objects via the keypad104. But the intended textual objects are ambiguous because some or all of the key presses individually represent multiple letters. The system100applies concurrent and competing strategies, which in this example include SKPL and multi-tap. Ultimately, the system100presents the user with a combined output, which contemplates interpretations from both of the competing strategies.

With this strategy, the result is more convenient to the user because it avoids any requirement for the user to change between a SKPL mode and a multi-tap mode. Furthermore, by providing both SKPL and multi-tap interpretations continuously, the device100may help a multi-tap user become more accustomed to using SKPL, or vice versa. It is also advantageous to the device manufacturer, who does not have to provide a separate mode key or determine which mode should be the default for each type of entry field.

A simple example is now discussed, using the example ofFIG. 1B. This drawing illustrates a moment in time. The user has previously entered, and the system has resolved, keypresses to form the words “I have a” as shown by158. The past text entry is not discussed further. However, after entering these keypresses (by whichever manner) to form “I have a” (158) the user in this example has continued entering keypresses. The new keypresses include the following sequence: “7788.” This discussion omits the steps and results of interpreting each keypress up to this point (e.g., “7” and then “77” and then “778” and so on), for ease of explanation.

Under the SKPL approach, the sequence “7788” must be interpreted so that each keypress represents one letter. So, each “7” could represent P or Q or R or S. Each “8” could represent T or U or V. At this point, the stem of only one entry in the vocabulary124of this example will match the key sequence so far—the word “sputter.” Therefore, under SKPL interpretation, the combination of keypresses so far is shown in the SKPL pane153as the stem “sput.” The system could also present the SKPL interpretation (so far) in the text pane152as the default interpretation at the text insertion point157, but this is implementation dependent, since the multi-tap interpretation produced so far (as discussed below) could be shown in the text pane152instead.

Under multi-tap, the sequence “7788” is interpreted with a different set of rules than SKPL. Generally, a new keypress of a given key signifies the first letter assigned to a key, but the second occurrence of the same keypress will signify the second assigned letter, and the third keypress will signify the third assigned letter. Of course, timing is an additional element of this strategy, but for ease of explanation, the present example assumes that the sequence “7788” has been entered without delay.

Under the multi-tap interpretation, the “77” represents a Q, and the “88” represents a “U.” So, the multi-tap interpretation (so far) is “qu,” which appears in the multi-tap pane154.

The system100prepares the completions pane155as follows. The system identifies each entry in the vocabulary124that begins with the multi-tap interpretation (here, “qu”) as well as each entry that begins with the SKPL interpretations (here, “sput”). The word completions possible under multi-tap include “question,” “quest,” “quiz,” “quill,” and many more. The only word completion possible under SKPL is “sputter”.

In the current example of the vocabulary124, the device100shows “question” and “sputter” in the pane155. The device100, accounting for the limited size of the pane155, prioritizes the list according to frequency or recency of use or context or other factors as discussed in greater detail below. The ellipsis shown in the pane155indicates that there are more proposed completions, but the pane is too small to show them all. To reveal additional completions, the user may employ an appropriate means of scrolling the pane, such as tapping the stylus on the ellipsis or pressing the right-arrow key repeatedly.

More Detailed Example

FIGS. 6A-6Eshow a more detailed, step-by-step, example. Without the need for individual marking, each of the screenshots6A-6E inherently includes the same panes152-156as shown inFIG. 1Band discussed above. Before this series of screen shots, the user has already entered and confirmed the words “Be at” which appear in the construction pane152at602.

InFIG. 6A, the user has just entered a “4” keypress, as shown in the pane156. The SKPL pane153interprets this as the word “I” or the letter “H” or “G.” The multi-tap pane154interprets the single “4” keypress as “G.” Possible completions based on vocabulary entries are those that start with “I” or “H” or “G.” The pane155shows some proposed completions. Due to space limitations, the pane155does not always have enough room to show all entries. Therefore, the system may order the proposed completions by context, frequency of use, recency of use, or other criteria, and leave out the lower-ranked entries that do not fit. As a different or additional embodiment, panes such as153-155may provide vertical and/or horizontal scrolling features, enabling the user to view larger respective lists.

InFIG. 6B, the user has immediately added another “4” keypress, so the pane contains “44.” The SKPL pane interprets the current keypress sequence (“44”) as “HI” or “II” or “IG” or “GH.” These are valid interpretations, since each corresponds to a complete word and/or the first two letters of an entry in the vocabulary. There may be other possible SKPL interpretations that are omitted from the pane153due to limited space, and indicated for example with an ellipsis. The SKPL approach may prioritize and limit display to the best alternatives.

The multi-tap pane154interprets the current keypress sequence (so far), two quick presses of the “4” key, as an “H.” Possible word completions include all vocabulary entries that start with an “H.” In some embodiments, such as this example, completions based on the one-letter multi-tap interpretation may be inhibited, to reduce the number of matches, or may be given lower priority. The pane155shows some proposed completions.

InFIG. 6C, the user has added a “6” keypress, so the pane contains “446.” Under SKPL, the current keypress sequence (“446”) is interpreted as the words “HIM” and “GIN” and the stem “IGN,” which begin longer vocabulary entries such as “HIMSELF” and “IGNORE”, etc. A prioritized subgroup of these appear (in pane155) as possible completions. The multi-tap pane interprets the current keypress sequence (so far) as an “HM.” In the displayed example, either no vocabulary entries match the multi-tap stem “HM” or the entries are low priority and do not appear at the top of the list of proposed completions.

InFIG. 6D, the user has added a second “6” keypress, so the keypress buffer pane contains “4466.” The SKPL pane153interprets the current keypress sequence (“4466”) as “IGNO” or “GIMM”. Vocabulary entries with these stems include words starting with “IGNO” and “GIMM,” and more particularly, words such as “IGNORE” and “GIMME” and so on. The proposed completions in pane155include these words. The “6” keypress follows immediately after the preceding keypress, so the multi-tap pane154interprets the current keypress sequence as “HN.” There are no matching vocabulary entries matching the multi-tap stem “HN.”

InFIG. 6E, the user has added a third “6” keypress, so the new word keypress buffer contains “44666.” The SKPL pane153interprets the current keypress sequence (“44666”) as “IGNOM”, the stem of the only matching vocabulary word remaining. The multi-tap pane154interprets the current keypress sequence as an “HO.” Thus, the proposed completions include entries that start with the stem “HO” (from multi-tap) and words that begin with the SKPL stem “IGNOM” (from SKPL). Some proposed word completions in pane155include “HOME” and “HOUSE” and “IGNOMINIOUS”, etc.

In the embodiment illustrated throughoutFIG. 6A-6E, the system100determines a “default word”, which may be a complete word or a stem, among all SKPL and multi-tap interpretation and completion strategies and displays this word or stem at the insertion point157. The device100shows the default word in bold to distinguish it from other items in the pane153.

In one embodiment, the default word is the first SKPL interpretation. In an alternate embodiment, the default word is the multi-tap interpretation and the multi-tap pane154may be hidden. In either case, the user may select an alternate word or stem or completion by various means, such as by pressing the device's arrow (directional scroll) and OK keys or by selecting it directly with a finger or stylus. This causes the device to replace the default word displayed at the insertion point157with the selected word.

Operational Details

Introduction

FIG. 5shows an operational sequence500in a broader sense, not necessarily constrained to the foregoing examples. Without any intended limitation, the sequence500is described in the context of the hardware fromFIG. 1Aas described above. Sequence500occurs in the context of receiving user input in a data entry field, message text editor, search form, or other application relevant to the purposes of this disclosure.

Keypress Input

In step502, the processor106and keypad104wait for the user to enter a keypress. In the present example, step502waits for the user to press one of the keypad keys “2” through “9,” since these are assigned to the letters A through Z as depicted inFIG. 1C. In step502, or at a later time, the processor106applies the key map122to identify the letters corresponding to key that was pressed. When step502senses an appropriate keypress, the routine500commences steps504aand504b.

Interpret & Complete

As illustrated, steps504aand506aoccur in parallel with steps504band506b. These steps need not start or finish at the exact same moment, but the general idea is that steps504a,506amay overlap to some extent in order to expedite the routine500. Of course, the events504a,506a,504b,506bmay occur in serial, at the expense of adding overall delay to the routine500.

In step504a, the processor106interprets the contents of the keypress buffer156(which now includes the keypress from step502) according to an SKPL interpretation. In brief, this involves searching a vocabulary database or traversing a tree structure using the current key sequence as an index key or its equivalent. Also in step504a, the processor106displays a reasonable number of SKPL words and word stems in the SKPL pane153. This may include all valid interpretations (by affording a scrolling or other automatic or user-driven advancing feature), or a limited set selected according to frequency of use, recency of use, context, or other factors. If the pane153can display only a subset of interpretations, the pane153may further include a representative symbol such as ellipses, scrolling bar, icon, etc.

Step506adetermines, for each of the interpretations from step504a, whether these interpretations constitute entries (or stems to entries) in the vocabulary124. In other words, step506adetermines whether each interpretation from504amatches an entry in the vocabulary124, or if one or more vocabulary entries form word completions of this interpretation. Thus, these longer entries represent possible (SKPL) completions of the user's keypress sequence in progress.

In step504b, the processor106conducts a multi-tap interpretation of the pane156. Also in step504b, the processor106displays this interpretation (or more than one, if others are possible) in the multi-tap pane154. Step506bdetermines whether the character combination from step504bmatches the first character(s) of entries in the vocabulary124(such that the vocabulary entry acts to complete the character combination), or even if it matches one of the vocabulary124entries outright.

In a simpler implementation, steps504a/506a(SKPL) and504b/506b(multi-tap) may be implemented as described above. However, these steps may be implemented differently to boost the efficiency of the overall operation. For example, the acts504a/506amay be integrated, and as with the acts504b/506b. Furthermore, the vocabulary124in this case may not even contain words or letters at all, and instead it may contain key sequences. Here, a word based vocabulary is broken into key sequences that would generate these words, so save the step of translating from key sequences into letters. This saves time in interpreting key sequences and then cross-referencing the vocabulary, since the operations can go straight from a keypress sequence to the proposed completions. Some of these operations may be carried out by traversing a tree, referencing a run-length-encoded table structure, or other such task. A number of other variations are also possible. For further information on these alternatives, reference is made to U.S. Pat. No. 6,307,548, and U.S. application Ser. No. 11/379,354. These documents are incorporated by reference into the present disclosure.

In step507, the processor106combines the possible SKPL and multi-tap completions (from steps506a,506b, respectively). In one embodiment, step507is achieved by aggregating the results of steps506a-506b.

In step508, the processor106operates the display102to present (in the completions pane155) some or all of the combined completions finalized in step507. Also at this time, the processor106may optionally update the display of the default word at the insertion point157. Optionally, step508may display a greater number of possible completions in the limited space of the pane155by affording a scrolling or other appropriate automatic or user-driven advancing feature.

Steps507and/or508: Managing Overall Results

Due to the likely limited screen size of the display102, measures may be taken to prioritize, reorder, trim, process, or otherwise modify the list of possible completions according to various strategies. This may occur in the act (step507) of combining the results from506a-506b, or in the presentation (step508) of the combined entries, or both.

In one example, steps507and/or508offer the most likely completion first, the next most likely second, and so on. This ordering is done so that the user can see and select a desired completion after the fewest number of inputs, avoiding time wasted in looking through a long list of irrelevant words. As one example, frequency of use in written text of each vocabulary entry may be a factor in determining which entry to offer first, and this factor calculated with other factors to come up with a numerical ranking. Each vocabulary entry may have an associated weighting value or an ordinal position which serves as its value. Other considerations as to order or prioritization of the presented list may include recency of use, alphabetical order, word length, etc.

Frequency of use refers to the use of static or dynamic frequency information in accordance with a linguistic model, which may include one or more of: frequency of occurrence of a word in formal or conversational written text; frequency of occurrence of a word when following a preceding word or words; proper or common grammar of the surrounding sentence; application context of current word entry; and recency of use or repeated use of the word by the user or within an application program.

Another option is for the device to alternate the completions from each interpretation (SKPL or multi-tap) without respect for relative use. Another embodiment favors completions that represent user-added words over completions of generic vocabulary words regardless of their basis on the SKPL or multi-tap interpretation. Furthermore, in certain contexts (such as password entry) the completions may be suppressed entirely, for example, to prevent inadvertent revelation of stored passwords.

Measures may be taken to ensure that step507saves the user some input effort, or gives preference to completions that have been selected before. Otherwise, word completions on short stems, such as a single letter “C”, begin a large number of vocabulary entries; but offering every word beginning with “C” is of no benefit to the user, and the processing required to identify them all may cause noticeable delays on low-powered handheld computers. Some techniques to address this include: (1) waiting to identify completions until after a predefined or user-selected number of letters have been entered, or (2) limiting identification of completions to those that exceed the number of keypresses by a given margin, etc. A complicating factor, however, is that users do not always look for or select a completion at the most optimal moment, and in fact some users (uncertain of the full spelling perhaps) might select a completion as soon as it is offered, so the most likely word completion may have to be offered earlier or later (i.e. during an input sequence that spells the beginning of that completed word) than would otherwise be necessary.

In some embodiments, steps504a,504b,506a, and/or506bmay be skipped entirely depending on the user's selected configuration. Furthermore, in other embodiments, some or all of steps504a,504b,506a, and/or506bmay extend the interpretation and completion logic to incorporate spell-correction techniques. For example, if the wrong key is pressed, or is pressed too few or too many times, edit distance or set-edit-distance calculations can suggest one or more corrected SKPL or multi-tap interpretations in addition to those matching the current keypress sequence. Some of these techniques are described in U.S. application Ser. No. 12/023,903 entitled SPELL-CHECK FOR A KEYBOARD SYSTEM WITH AUTOMATIC CORRECTION, filed Jan. 31, 2008 in the name of Kay et al.

In addition to processing the overall list of completions as discussed above, the device may take steps to balance, tune, and prioritize the SKPL and multi-tap sets of completions relative to each other. Each set of completions (namely, SKPL and multi-tap) might contain more entries than can be shown on the small display, and these steps ensure that one set does not crowd out the other set unless or until it is evident which of the two interpretations the user is relying on for the current key sequence. Therefore, the prioritization of SKPL and multi-tap entries discussed herein concerns acts to show more entries from one interpretation than the other, increase screen size devoted to one interpretation, order lists to favor one interpretation, and the like.

As another example, step507may be performed to favor SKPL over the multi-tap interpretations until there are insufficient SKPL-based completion choices, at which point the multi-tap interpretation becomes a higher priority for completions. This is based on the insight that multi-tap input sequences feature many repeated presses of the same key, which is far less common in SKPL input sequences; with SKPL, repeated presses of the same key quickly eliminate many of the vocabulary entries. For instance, given the key mapping inFIG. 1C, if the user made four presses of the “8” key, this is easily interpreted as a multi-tap “S.” However, with SKPL, the repeated entry of the same key narrows down the choices significantly; the system could only match vocabulary entries containing four consonants in a row in this case (selected from “P”, “Q”, “R”, and “S”). In most languages a vowel occurs in every syllable, so a word with four consonants in a row would be rare. The lack of completions based on SKPL interpretations can serve as a signal to the system of the user's intent to employ or favor multi-tap, in addition to allowing room for more multi-tap-based completions if the list is limited in length.FIG. 1Bshows an example of this condition, where the multi-tap-based completion “question” is listed first as it is a more likely word than the SKPL-based completion “sputter”. Thus, the device may prioritize the SKPL interpretations (in number, display area, order, prominence, etc.) until the vocabulary entries arising from SKPL falls below a prescribed threshold.

Some other options for prioritizing display of SKPL versus multi-tap interpretations include:Prioritizing completions of SKPL interpretations when the current key sequence has few or no repeated keys, which suggests that the user is not currently employing the multi-tap method. Alternatively, prioritizing completions of multi-tap interpretations when the current key sequence has repeated occurrences of the same key being pressed, occurrences of repeated keypresses of one key followed by repeated keypresses of another key, etc. This analysis of the contents of the key sequence (for determining whether to favor SKPL or multi-tap) occurs apart from the interpretation of the key sequence.Watching for predefined entries via the keypad (or another data entry tool), where the predefined entries are particular to SKPL or multi-tap. For instance, this approach may prioritize completions of the multi-tap interpretation when a “timeout kill” (such as the right arrow key) has been used, which suggests that the user is currently employing the multi-tap method.Favoring SKPL over multi-tap (or vice versa) according to application context. For instance, SKPL interpretations may be favored for open text fields, and multi-tap favored when the user is engaged in entering text unlikely to be in the vocabulary, such as an email address, phone number, name, address book entry, ISBN, etc.Monitoring the user's selection of presented entries (step509), and tracking whether the user selects SKPL or multi-tap entries. Then, the device prioritizes the combined list to favor the entries arising from the favored interpretation strategy. The tracking of user selection may be based on total numbers, recent selections, selections made in certain contexts, etc.Monitoring the user's cadence in keypress entry (502), since multi-tap keypresses will likely have one timing, and SKPL keypresses will have a another timing.

The preceding strategies are automatic and do not require user awareness or deliberate action. Other options may be based on how the user has configured the system. For example, if the user selects a configuration where the multi-tap interpretation is the default (where for example the multi-tap interpretation might also appear at the insertion point157), then in step507the processor106can prioritize the completions that are based on the multi-tap interpretation identified in step506b.

In another example, the user may use the stylus or key or key sequence to resize or hide the respective segments of a list (vertical or otherwise) of interpretations and completions (where one segment contains SKPL completions and the other contains multi-tap completions). In doing so, the user indicates a relative importance of the multi-tap completions versus SKPL completions. As a more particular example, step507may vary the relative numbers of vocabulary entries arising from SKPL versus multi-tap interpretations according to a user-submitted ratio. The ratio may be entered by adjusting a slider, indicating a numerical blend, changing the size of a GUI feature, adjusting a dial, operating a pull-down menu, or many other ways. As a variation of this, the device may represent vocabulary entries arising from SKPL analysis in one pane, and those arising from multi-tap analysis in another pane, and vary the relative sizes of the panes according to the user-submitted radio.

Iterative Alternative

In a different embodiment, some or all of steps504a,504b,506a,506b,507, and508may be limited as follows. Namely, steps506a-506bterminate prematurely (with respect to a full analysis of all possible completions) as soon as these steps reach a prescribed number of completions, either jointly or singly. These truncated results are combined and presented in steps507-508, and if the requests to view further entries, then steps506a-506bare reinitiated. The user request, for example, may occur in the form of scrolling through a list, operating a pulldown menu, pressing a designated key or key combination or key sequence, etc. This approach speeds the completion of steps506a-506b, and avoids further calculations until actually needed.

Further Action

After step508presents some interpretations and completions of the user's keypress entry so far, step509waits for user input. Depending upon the nature of the user input, step509can progress in various ways. For one, the user may take action (509a) to begin activity (512) completely unrelated to keypad driven text entry. For instance, the user may operate the device100to place a call, play a game, start an unrelated application program, or perform another function. In some embodiments, taking such an action automatically confirms the default interpretation. In contrast to this, the user may add to the keypresses so far by entering (509c) another keypress. In this event, the routine500returns to steps504a,504b, to begin processing the keypress sequence as supplemented by the new keypress.

In contrast to user actions509aand509c, the user may choose (509b) one of the SKPL interpretations displayed in the SKPL pane153, the interpretation displayed in the multi-tap pane154, or one of the proposed completions displayed in the completions pane155. The user may carry out this choice in various ways, such as by pressing the Space key and implicitly accepting the default word, by first pressing one or more arrow keys (and/or the OK key) to change the selection from the default, or by tapping on the word directly with finger or stylus. There may be further variations (not shown) to the preceding user options, such as when the user has changed the default selection but not accepted the word yet, and even may be able to continue pressing letter keys. In this case the processor106remains at step509, and either continues to step510if the user chooses a proposed completion, or returns to steps504a,504bif the user continues entering key presses.

When the processor106detects that the user has chosen (509b) one of the displayed alternatives, the device100performs step510. Here, the processor106optionally operates the display102to change the default or selected interpretation shown to the selected interpretation or completion (from the panes153-156) that the user elected in step509b. Henceforth, this word will be part of the words (158) that the user has entered and confirmed. The new word under construction, at this point, will be empty pending the entry of some new key presses.

After step510, the processor106waits for other input (510a) or a new key press (510b), which lead to resulting actions as discussed previously.

Alternative

The following example provides an alternative for certain aspects of the sequence. Namely, this example uses the following context for user entry of keypresses—entering a search term for the device100to execute. In this embodiment, instead of presenting the SKPL word and stem interpretations in a separate pane, the processor106presents them in situ with the search results. In this embodiment, then, the body or bodies of text being searched serve as the vocabulary124.

FIG. 7shows an example. In this screen shot, the display includes a multi-tap pane704(which acts like the multi-tap pane154ofFIG. 1B), and a numerical keypress buffer702(which acts like the buffer156ofFIG. 1B). Instead of the completions pane155, the device100presents a search results pane710. This pane710indicates where the current key sequence has (at least partially) matched the search results (such as706for the SKPL interpretation of the current key press sequence, and708for the multi-tap interpretation of the current key press sequence), within the text of each matching search result. In the present example, the pane710shows search results from a combined search of an address book, stored music, and Internet web sites.

In the embodiment ofFIG. 7, then, the user first initiates a search operation (not shown). Then, the sequence500is performed to assist the user in spelling out the desired search terms. The output, in the form of the search results pane710, is presented in step508. The search results are integrated with the body of text being searched. At this point, the user can proceed to an unrelated task (such as starting a different application, placing a call, etc.), as shown by steps509,509a. Or, the user can continue entering keypresses, as shown by steps509,509c.

Or, the user can choose one of the displayed search matches (from the pane710), which occurs in step509b. In this event, the device100proceeds to step510, which (instead of the function as displayed inFIG. 5) acts to provide a more complete listing of the item found in the search and prompt the user for confirmation, or automatically activate the found item by playing a found song, calling a found address book entry, navigating to a web site address, etc. Step510bin this embodiment is inapplicable, if the prompted action is answered by a non-letter key input.

Other Embodiments

While the foregoing disclosure shows a number of illustrative embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims. Accordingly, the disclosed embodiment are representative of the subject matter which is broadly contemplated by the present invention, and the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims.

All structural and functional equivalents to the elements of the above-described embodiments that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the phrase “step for.”

Furthermore, although elements of the invention may be described or claimed in the singular, reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but shall mean “one or more”. Additionally, ordinarily skilled artisans will recognize that operational sequences must be set forth in some specific order for the purpose of explanation and claiming, but the present invention contemplates various changes beyond such specific order.

In addition, those of ordinary skill in the relevant art will understand that information and signals may be represented using a variety of different technologies and techniques. For example, any data, instructions, commands, information, signals, bits, symbols, and chips referenced herein may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, other items, or a combination of the foregoing.

Moreover, ordinarily skilled artisans will appreciate that any illustrative logical blocks, modules, circuits, and process steps described herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.