CA2141011C

CA2141011C - Stylus-based keyboard key arrangement

Info

Publication number: CA2141011C
Application number: CA002141011A
Authority: CA
Inventors: Karrie Jo Hanson; Gregory Peter Kochanski
Original assignee: American Telephone and Telegraph Co Inc
Current assignee: AT&T Corp
Priority date: 1994-02-23
Filing date: 1995-01-24
Publication date: 1999-01-26
Anticipated expiration: 2015-01-24
Also published as: CA2141011A1; EP0670554A2; EP0670554A3; JPH07261896A; US5483235A

Abstract

A small, stylus-based keyboard in which the arrangement of the keys is a function of predetermined estimated probabilities of the occurrence of variouspossible sequences of keystrokes. Sequences of keystrokes which are estimated tohave a high likelihood of occurrence result in the associated keys being placed adjacent to one another. In this manner, the ease, speed and accuracy of use of small, stylus-based keyboards may be improved. Multiple keys representing the same character may be provided to increase the likelihood that keys included in high probability sequences will be adjacent. The probability estimates may be determined based on a statistical analysis of a preselected sample of text. In addition, keys may be color-coded for ease of identification and grooves may be cut into the housing between adjacent keys for ease of stylus operation. Lights (e.g., light-emitting-diodes) may also be inserted between adjacent keys or beneath the keys for purposes of word identification or next letter prediction.

Description

2141~11 STYLUS-BASED KEYBOARD KEY ARRANGEMENT

Field of the Invention The present invention relates generally to the field of alphabetic or alph~ ."~. ;c keyboards for information input devices and specifically to the 5 arrangement of keys for a stylus-based keyboard in which text is entered by touching a stylus to s~ccescive letters on the k~yboald.
Back~round of the Invention As people have become more accustomed to electronic methods of col~""~ tion, data manipulation and information proces~ing in their jobs and in 10 their personal lives, the need for portability of the electronic devices which pclroll,l these tasks has increased. One goal, for example, has been to produce quite compact devices which have the combined capabilities of a desktop or laptop colllpul~" acellular telephone, a fax m~~hinP, and more. Such devices are commonly referred to as personal co~ ic~tors.
The technological limits of portability have often been domin~ted by the limitations of power supply technology -- that is, by the weight and size limit~tions of current battery technology. However, an area that has been given less attention is the input keyboard usually associated with these devices. Most designs of portable comyuliilg devices have retained the use of the conventional "QWERTY" keyboard 20 because of its f~mili~rity. However, to include the QWERTY keyboard in a portable colll~uling device limits the decigner's ability to reduce the size of such a device, since sufficient width is required to accommodate two hands side by side. QWERTYkeyboards which are smaller than 8 inches across tend to be very difficult to use in a touch-typing mode quickly. Thus, a one-finger "hunt and peck" action may be 25 required. Moreover, it is necess~ry to take care with such small keyboards to avoid fingers touching more than one key at a time.
One approach that is presently being pursued is to elimin~t~ the need for a keyboard altogether. In particular, portable colllpuling devices are now available which accept han-lwliuen input, provided with use of a stylus or similar pen-like 30 tool. These devices make use of handwriting recognition software to inlt;ll,let the user's han-lwlillen input and to convert it to an equivalent int~rn~l represent~tion (e.g., in ascii text form).

~41~11 At least two problems result from this approach. First, the algo~ilhll~ic comp~exity required for reasonably accurate handwriting recognition ~;ullGIllly requires substantially more proce~in~ power than do many of the applications otherwise provided on such portable co~ uling devices. The.GfolG, these devices S may need to be far more costly with the use of conventional han-lwlillGn inputtechniques than with keyboard-based input techniques. Moreover, the power requirements for a processor capable of ~Ço"~fing reasonably accurate handwriting recognition can be substantial.
Second, most handwriting recognition software available today has an 10 input error rate ~ignific~ntly higher than that typically achievable with the use of keyboard input. Although sophi~tic~t~d handwriting recognition techniques often include error correction capability, the complexity and variability of handw,;llG"
input often results in less accurate input text than does text typed in through a keyboard.
One ~lt~ tive approach which has been suggested is a stylus-based keyboard design in which text is entered by touching (or otherwise coupling) a stylus to succes~ive keys on a keyboard. A device co~ ing such a stylus-based keyboard can be de~ign~d to be comparable in size to a device based on handwriting recognition. Moreover, it can have a much lower error rate with significantly less 20 procec~ing power requirements. Thus, stylus-based keyboards can allow for the construction of low-end (i.e., low cost) portable co",~ulh~g devices.
Summary of the Invenffon The present invention recognizes the fact that the ease, speed and accuracy of use of a stylus-based keyboard is limited by the rli~t~n~e that the stylus 25 must travel between keys which are to be typed consecutively. Th~,lcfore, it would be advantageous to arrange the keys on a stylus-based keyboard so that keys which are more likely to be typed in imm~ te succes~ion are placed in closer proximity to one another than keys which are less likely to be consecutively typed.
Specifically, the present invention provides an information input device 30 (e.g., a keyboard) ~ pted for input of natural language text. The input device has a plurality of discrete areas (e.g., keys) represen~live of characters which can be combined to produce such text. These discrete areas are ~l~pted to be activated by o~alively coupling a stylus thereto. (The stylus may, for example, be a hand-held mechanical device or even a human finger.) The arrangement of the discrete areas35 on the input device is a function of predete~ l~.in~d estim~ted probabilities of the -activation of one or more possible sequences of discrete areas, wherein the proba~ilities are a function of the natural language text.
Activation probabilities are determin~d for one or more sequences of discrete areas. Then, the discrete areas are arranged as a function of these 5 probabilities. Specifically, of those sequences which have been estim~ted to have a likelihood of activation higher than a predetermined threshold, a majority (i.e., more than half) are selected. For each selected seql~çnce, the collcsponding discrete areas are placed "adjacent" to one another on the input device. In this manner, the ease, speed and accuracy of use of stylus-based input devices may be hlll~roved.
As used herein, the term "adjacent" is used with respect to the discrete areas on the information input device (e.g., the keys on a keyboard) to mean that the discrete areas are positioned in close proximity to each other relative to the proximity of other discrete areas thereto. Specifically, two discrete areas are defined to be ~dj~cçnt if and only if the ~lict~n~e bclwcell their lesl)e.;livc centers is less than 15 or equal to 175% of the larger of (a) the tlict~nre between the center of the first of the two discrete areas and the nearest center of any other discrete area and (b) the~lict~n~e between the center of the second of the two discrete areas and the nearest center of any other discrete area. (The "center" of a discrete area is the point located at the center of the cm~ st circle which may be circllmcçrihed around the discrete 20 area.) In other words, two discrete areas are adjacent if they are not more than 1.75 times as far apart as one of the two discrete areas is from its nearest "neighbor."
The probability estim~tes may be dete~ ed based on a st~ticti~l analysis of a preselected sample of text. In addition, keys may be color-coded for ease of i(1~ntifi~tion and grooves may be cut into the housing bc~wcen ~dj~ ent keys 25 for ease of stylus operation. Lights (e.g., light-emitting-diodes) may also be inserted between ~dj~ce~t keys for purposes of word identifi-~tion or prediction. Moreover, multiple keys rcp~sçntinp the same character may be provided to increase the likelihood that keys in- luded in high probability sequences will be adjacent.
Brief Description of the Drawin~s Figure 1 diagrams the major components of a portable com~ulil1g device comprising a stylus-based keyboard with keys arranged in accor~allce with an illu~ iv~; embodiment of the present invention.
Figure 2 shows the portable co,..l.uling device of Figure 1 in further detail.

2~11011 Figure 3 shows a m~gnified view of a portion of the keyboard of the portable co~ uLing device of Figure 2, illustrating that light-emitting-diodes are positioned between n~lj~,ent keys.
Figure 4 is a flow diagram of a method of arranging keys on a keyboard 5 in accordance with an illustrative embodiment of the present invention.
Figure 5 shows a teleco........~ir~tions device comrricing a keyboard having keys arranged in accordance with an illu~ ive embodiment of the present invention.
Detailed Description A portable co--.~ g device comrri~in~ a stylus-based keyboard with keys arranged in acconlance with an illu~ ive embodiment of the present invention is shown in Figures 1-3. Figure 1 diagrams the major co~ onell~s thereof.
Specifically, housing 28 contains keyboard 14, processor 30 and display device 20.
Keyboard 14 serves as an input device to processor 30, and display device 20 serves 15 as an output device from the processor. As such, both keyboard 14 and display device 20 are elertrir~lly coupled to processor 30.
As can been seen from the more detailed illustration in Figure 2, keyboard 14 is physically mounted atop housing 28. Keys 12 of keyboard 14 comprise alphabetic letter keys r~p~senlalive of the letters A through Z for use in 20 entering F.ngli.ch language text. Also included are nllmrrir, keys represel ~live of the digits 0 through 9, a "space" key, an "enter" key, and special function keys F1 through F10. Keyboard 14 is operated by touching stylus tip 18 of stylus 16 to asequence of keys 12 -- that is, a given key is typed by touching stylus tip 18 to the key.
"~l~rrn~e" ("ALT") and "control" ("CTRL") operations may be pe-~-~ed by depressillg a co..~,i,pollding button either on one of the sides of keyboard 14 or on the body of stylus 16. The "shift" operation may be pelrollnedeither by deplessillg a button on one of the sides of keyboard 14 or by exertingincreased pressure on stylus tip 18. Any punrtll~tion marks or other symbols that do 30 not appear on keyboard 14 may be drawn by hand on conventional .cign~tllre pad 26 and recognized by conve.llional handwriting recognition software. Note that handwriting recognition software whose task is limited to recognizing plmrtll~tion marks and special ch~a~ is much less complex than general handwriting recognition software. The illustrative portable co~ u~ g device shown in Figure 2 35 also includes display 20, mouse pad 24, phone jack 22, and, intern~l to the device, , processor 30 (shown in Figure 1 but not in Figure 2), all of which are of con~ tional design. Mouse pad 24 enables stylus 16 to be operated as a conventional CO111~UIGI "mouse" device and phone jack 22 enables the portable colll~u~ g device to be connectecl to a (wired) teleco....,.-l,~ tions channel.
The keyboard as shown in the figure may be built on a small, hand-held base as small as approximately 3 inches square (i.e., 3" by 3"). Note that typing with such a hand-held keyboard requires no arm motion or grip changes, and uses motions very similar to those used in handwriting or in taking shorthand.
A keyboard arrangement in accordance with the present invention may 10 be arrived at by, for example, detçrmining the most commonly occurring sequential letter pairs in Fngli~h language text and, possibly, the most commonly occllrrin~
letter triplets as well. Specifically, the probability that an a~ d,ily located two letter sequence in an excerpt of F.ngli~h language text will consist of a given pair of letters may be estim~ted This probability may then be co~ uGd to a predeterminPrl 15 threshold value, such as .006, for example. For most of (i.e., the majority of) the sequences for which the coll~sponding probability çY~e.ls the threshold, keys lcplesenldtivG of the letters in the sequence are placed ~ cent to one another. In certain embodiments the "space" character is included as one of the "letters" which comprise the evaluated letter seqU~pnres For example, the sequence "e_" (i.e., the 20 letter "e" followed by a space) is quite common, since many common words end with the letter "e."
In one illu~lldtive embo~limpnt~ the predete~ ed threshold may be del~. ."inçd based on the esli,,.nlP~d probabilities of the letter sequences. For example, it may be desirable that the "n" most common letter pairs (or a majority 25 thereof) be lcplesented by adjacent keys. The probabilities of all possible letter pairs may be estim~ted and the letter pairs may then be listed in descentling order of their probabilities. The probability of the "n+l'st" listed letter pair may then be used as the predete....;..~-~ threshold. In this manner, the "n" most common letter pairs will have probabilities which exceed the threshold.
Probabilities of three letter sequçnces may also be estim~tP,d in a similar manner, and these probabilities may be colllpared to another threshold, such as .002, for example. If the probability of a given triplet (i.e., a three letter sequence) exceeds this threshold, the keys representdtive of the given sequence may be placed ~dj~cPnt to each other for a selected number of these sequences. Specifically, a key 35 represçn~livG of the first letter of a selected triplet is placed ~Ij~,Pnt to a key represçnl;~ivG of the second letter of the triplet, and a key ~el?rGsenlative of the third 21~1011 letter of the triplet is placed adjacent to the key representative of the second letter of the triplet. In this manner, common letter triplets, like the common letter pairs, may be entered quickly by a user of the keyboard (i.e., with minim~l hand motion).
In the arr~n~em~nt of the keys for the illustrative keyboard shown in 5 Figure 2, for example, probabilities for certain letter pairs and certain letter triplets were estim~tçd and the most commonly occurring sequçnces were thereby dete~ led. For example, note that representalive keys for the common two-letter sequences "ER," "IN" and "TH" are adjacent, as are representative keys for common three-letter sequences "THE" and "ING." Specifically, each of the letter pairs E and 10 R; I and N; H and T; I and T; A and T; E and T; N and O; A and N; E and S; A and R; E and N; O and R; E and H; E and L; A and L; I and S; S and T; D and E; O andT; and C and E was ~ieterminçd to have an estim~ted probability greater than .006.
Of these, a majority (actually seventeen out of twenty -- all but A and N; E and S;
and C and E) were select~l and keys for each selected pair were positioned ~dja~ent 15 to each other on the keyboard shown in Figure 2. Moreover, each of the lettertriplets T, H and E; I, O and N; I, N and G; A,N and D; T, I and O; E, N and T; and E, T and A was dete....;ned to have an e~li", ~Pd probability greater than .002. Of these seven triplets, six (all but A, N and D) were also selected, and keys for each selected triplet were placed adjacent to each other as well.
The above described probabilities for selected letter pairs and triplets may, for example, be estim~ted based on a st~ti~ti-~l analysis of a preselected sample of F.ngli~h language text. That is, conventional st~ticti~l analysis techniques may be applied to (p~felably) large qu~ntities of sample textual data to estim~tç the probability that each possible sequence of letters less than a given length will occur 25 in the text which is to be input through the keyboard. For example, as described above, letter pairs and triplets (ie., sequences less than 4 characters in length) may be analyzed to det~ ine the most common sequçn.~.es (i.e., those having probabilities greater than one or more predele....;~-~.d thresholds).
Where a particular application is envisioned for the use of the keyboard, 30 sample input text for that given application may be advantageously used to produce an improved application-specific keyboard arr~ngem~nt ~ ;vely~ however, a standardized keyboard arrangement for all applications may be advantageously produced by using a wide variety of sample textual data. Note, however, that dirrelcnt languages (e.g., Spanish or French as opposed to F.ngli~h) may well have 35 dirr~ t letter sequence probabilities. Thus, it may not be advantageous to produce a single standard keyboard arr~ngçmPnt for use with dirrt;l~ t languages.

2 1 ~

In the illu~llativ~ keyboard of Figure 2, common letters such as "A" and "E" have been ~c~igned more than one representalive key . By providing duplicatekeys for the same commonly occurring character, the likelihood that keys in~hlde~l in high probability sequences can be arranged so as to be adjacent is increased. In other 5 words, it will thereby be possible to place more letter pairs (and triplets) adjacent to one another. For example, it has been estim~ted (~c~u~ g general Fngli~h language text) that with the key arr~n~m~nt shown in Figure 2, there is a probability of approximately 50% for each letter to be entered that a key lciplese~ v~ of that letter will be adjacent to the previously typed key. Such a probability of sequentially 10 typed keys being adjacent may be del~ ined based on a (preferably large) sample of F.ngli~h language text (as in the above-described method for estim~ting sequence probabilities). Moreover, such a probability may be used ~ one possible "quality"
measure of a given keyboard. (Other possible quality measures may, for example, take into account the actual ~ t~n~es be~weell sequentially typed keys. Moreover, 15 these (li~t~n~es may be "weighted" depending on the relative location of the respective keys, since it may be faster to move one's hand a given tli~t~nce between keys in one area of the keyboard than in another area of the keyboard.) In accordance with one illustrative embodiment, the arr~ngem~nt of the keys produced in accordance with the principles of the present invention may be 20 further illlprl)v~d by use of an ilelalive technique which strives to "m~ximi7.o" a quality measure such as the one described above. For ex~mple, the quality measure may be det~rmin~d for both a given keyboard and for a slightly modified version of that keyboard in which an ~IJilldlily chosen pair of keys are switched with one another. (The chosen pair of keys may or may not be limited to ~dj~r-ent keys.) The 25 version of the keyl~ard with the higher quality measure is ret~in~-l, and this process is repeated nulll~loUS (e.g., thousands of) times. In this manner, a keyboard having a high probability that sequentially typed keys will be adjacent is gell~,.a~d.
In one ~l~ern~tive embodiment incorporating such a ma~ illli;~lion technique, the version of the keyboard having the higher quality measure may be 30 retained most, but not all, of the time (ie., with a high probability less than one). By occasionally retaining the lower quality keyboard instead of the higher quality keyboard, the procedure may advantageously avoid becoming "stuck" at a "local m~ximllm " In yet another ~lt~rr~tive embodiment, such a m~ximi7~tion technique may be applied using the above-described quality llle&SUle without first ~lrOllllillg 35 any particular initial arrangement of the keys (e.g., by starting with a random arrangement). Given a sufficient number of iterations, a keyboard arrangement in 2141~11 accordance with the present invention will likely be produced.
Figure 4 is a flow diagram of a method of arranging keys on a keyboard in accordance with one illustrative embodiment of the present invention. The procedure shown selects all of the seq~len~ es of letter pairs having the "N" highest 5 estim~te~l activation probabilities (as described above), arranges the keyboard so that the keys in each of these sequences are adjacent, and then pelrolllls the above-described m~ximi7~tion technique.
Specifically, step 52 Cletç~ f ~; e~ ed activation probabilities for all two- letter sequences, and step 54 selects all of those sequences having the "N"10 highest probabilities. (Other embo~ may select less than all, but more than half of the sequences having an estim~ted activation probability above a given threshold.) Step 56 then arranges the keyboard so that the keys in each of theseselecte.l sequences are ~dj~çent Step 58colll~ules a quality measure (e.g., the probability that sequentially activated keys are ~rli~e~t) for the "origin~l" keyboard, 15 and step 60 gel1el~les a "modified" keyboard by ~wiLchillg an ~I,iLI~ily chosen pair of ~dj~cent keys. Step 62colll~ules a quality measure of the modified keyboard and decision 64colllpares it to the quality measure of the origin~l keyboard. If thequality measure of the modified keyboard is the greater of the two measures, step 66 replaces the original keyboard with the modified keyboard and step 68 20 collespondingly updates the quality llle~lrc. Decision 70 determin~s whether the predetçrminçd number of iterations have been pelrolllled, and, if not, the procedure returns to step 60 for the next iteration.
In accordance with certain illu~ ive embodhl~~ of the present invention, the keys may be categorized and collcspondingly color-coded to assist the 25 user in key identifil~fion. For example, in one embo-lim~nt vowel keys and keys for various portions of the alphabet may be provided in dirrelent colors. Altçrn~tively, the keys may be color-coded based on their location on the keyboard. In the illustrative embodiment shown in Figure 2, for example, the three "rings" of keys (the inner ring, the middle ring and the outer ring) are each color-coded with a30 dirÇ~lclll color. By color-coding the letter keys as shown in Figure 2, once a keyboard user begins to associate each letter with a particular color, it will be easier for him or her to quickly locate the key during typing.
According to certain illusllalive embo-lim~-nt~, grooves 32 as shown in Figure 2 may be cut into the keyboard housing betwce~ çnt keys to provide for 35 guided movement of the stylus bcl~eell them. In this manner, the speed and accuracy of use of the stylus may be increased.

2~ 41~1~

In addition, lights 34 (e.g., light-emitting-diodes) may be provided betwe-en ~ rçnt keys, as is illustrated in the m~gnifiçd view of a portion of the keyboard of Figure 2 which is shown in Figure 3. For example, the sequence of lights (and collcspollding keys) representing a given typed word may be illllmin~ted 5 (or flashed) upon its con~letion. The completion of a word may, for example, be indicated by the typing of a "space" key. That is, upon the typing of a space key, the previous sequence of keystrokes (since the last space key was typed) is p~i,ull~ed to represent a word. By illllmin~ting the lights bclween the ~dj~cent keys which were typed since the previous space key, a pattern representing that word is illllmin~t~d 10 As an ~Itçrn~tive use of lights 34, one or more of the lights bclween the last key typed and ~djacer-t keys may be illllmin~ted to in-lir~te options for the next character or flashed to in-lir~tç a predicted next letter. In ~Itern~tive embo~lim~nt~ lights 34 may be positioned within (or beneath) the individual keys, rather than bcLwcell adj~rçnt keys. These lights may then be used in an analogous manner to the uses 15 described above.
Figure 5 shows a telec~,.l....~.~içations device compri~ing a keyboard having keys arranged in accordallce with an illustrative embodiment of the present invention. Specifically, the device shown in the figure is a telephone hand-set compri~ing housing 42 which inrhl-lçs a full alphabelic keyboard having keys 12 20 arranged in a similar manner to the keyboard included in the portable co"l~uling device of Figure 2. The telephone hand-set of Figure 5 also inrhldes microphone 44 and loudspe~k~r 46. Teleco.... -ic~tions devices cQl~t~i"il-g alphabetic keyboards (not arranged in accoldallce with the present invention) are convelllional. For example, teleco........,.ir~tions devices for the deaf (TDDs) commonly provide a25 standard QWERTY keyboard for the typing of mPss~ges which may be tr~n~mitted across a conventional telec~.. l.-ir~tions network. Keys 12 of the telephone keyboard shown in Figure 5 may be operated with use of one or more fingers or, ~ltPrn~tively, with a hand-held mechanical (e.g., pen-like) stylus.

Although the above discussion has described illustrative embo-limrnt~
30 of the present invention in which the input device is a stylus-based keyboard, the present invention is not limited to keyboards or devices col-t~il-il-g keyboards. Any input device having a plurality of discrete areas, each area ~l~pted to be activated by opelalive;ly coupling a stylus thereto, is int~n/le~l to be included within the scope of the present invention. In addition, the opelalive coupling may be electrical (e.g., 35 capacitive or electrostatic), m~nrtir" optical (where, for example, the stylus may be a "light-pen") or m~ch~nic~l (as it is in the case of a keyboard). Moreover, the stylus used fo operate the input device may be a mechanical (e.g., hand-held) pen- likeobject or it may even be a human finger. For example, a co,lv~;nlional CO~l" uler mouse may be modified so as to include keys (representing alphabetic letters) S adapted to be activated by the use of one or more fingers, wh~ ,in the keys have been arranged in accordance with the present invention -- such a device is included within the scope of the present invention. Moreover, conventional-style keyboards (i.e., those int~n-led to be operated by the use of one or more fingers from one or both hands) are included within the scope of the present invention as well.
As used herein, the phrase "portable colll~ulillg device" is intended to include any portable device compricing a processor, a display, an input device and a housing therefor, including portable and laptop COlll~ulc,S, as well as the class of devices commonly referred to as personal col ", ,l,U~ic~tors (or personal digital commllnic~tors). These latter devices commonly include modems or similar devices15 for ll~r,~",;ll;ng and receivillg data across a teleco-...----.-ic~tions ch~nn~l, and may, in particular, further include means for wireless (e.g., cellular) col"".--.,ication. (The use of the term "processor" should not be construed to refer exclusively to hardw~c capable of executing software.) In addition, the phrase "teleco",l"l.i-ications device" as used herein is 20 intended to include any telephonic instrument which incllldes a keyboard. As such, conventional desk-top or other corded telephones, cordless and cellular telephones, as well as f~csimile m~rhinPs, all fall within the scope of the present invention if they include a keyboard arranged in accordal1ce therewith.
Although a number of specific embo~lim.qnt~ of this invention have been 25 shown and described herein, it is to be lln-lerstQod that these embo(lim~nt.~ are merely illustrative of the many possible specific arrangclll~ which can be devised in application of the principles of the invention. Numerous and varied other arr~ngem.ont~ can be devised in accordance with these p,inciples by those of ordinary skill in the art without departing from the spirit and scope of the invention.

Claims

1. A method of arranging a plurality of discrete areas on an information input device, the input device adapted for input of natural languagetext, the discrete areas representative of characters, said characters combinable in sequence to produce the natural language text, the discrete areas adapted to be activated by operatively coupling a stylus thereto, the method comprising the steps of:
determining, for one or more sequences of two or more of said characters, an estimated probability of the discrete areas representing said characters being activated in sequence, said probability being a function of said natural language text;

selecting a majority of the sequences which have been determined to have a corresponding probability higher than a predetermined threshold; and arranging the discrete areas on the input device as a function of said estimated probabilities, the discrete areas representing characters included in each of the selected sequences being positioned adjacent to each other on the input device.

2. The method in accordance with claim 1 wherein one or more of said characters are represented by more than one of said discrete areas.

3. The method in accordance with claim 1 wherein the arranging step comprises arranging the discrete areas on the input device in a plurality of concentric geometric figures.

4. The method in accordance with claim 1 wherein the natural language text comprises English language text and wherein the characters includealphabetic letters A through Z.

5. The method in accordance with claim 1 wherein the step of determining the estimated probabilities comprises performing a statistical analysis on a preselected sample of said natural language text.

6. The method in accordance with claim 1 further comprising the steps of:
computing a first quality measure as a function of said arrangement of discrete areas resulting from the arranging step, the first quality measure reflecting a probability that successive characters in said natural language text are represented by adjacent discrete areas of said information input device comprising said arrangement of discrete areas;

modifying said arrangement by switching the positions of two or more of said discrete areas;

computing a second quality measure as a function of said modified arrangement, the second quality measure reflecting a probability that successive characters in said natural language text are represented by adjacent discrete areas of said information input device comprising said modified arrangement of discrete areas; and choosing one of said arrangement and said modified arrangement as a function of said first and second quality measures.

7. An information input device adapted for input of English language text, the input device comprising a plurality of discrete areas representative of characters including the alphabetic letters A through Z, the discrete areas adapted to be activated by operatively coupling a stylus thereto, wherein the input device comprises at least eleven pairs of adjacent discrete areas, each of said pairs of adjacent discrete areas comprising areas representative of a pair of characters selected from the group consisting of E and R;I and N; H and T;

I and T; A and T; E and T; N and O; A and N; E and S; A and R; E and N; O
and R; E and H; E and L; A and L; I and S; S and T; D and E; O and T; and C
and E.

8. The input device in accordance with claim 7 wherein the input device further comprises at least two triplets of discrete areas, each discrete area in each one of said triplets being adjacent to another discrete area in the one of said triplets, each of said triplets of discrete areas comprising areas representative of a triplet of characters selected from the group consisting of T, H
and E; I, O and N; I, N and G; A,N and D; T, I and O; E, N and T; and E, T and A.

9. The input device in accordance with claim 7 wherein one or more of said characters are represented by more than one of said discrete areas.

10. The input device in accordance with claim 7 wherein the discrete areas are arranged on the input device in a plurality of concentric geometric figures.

11. The input device in accordance with claim 7 wherein the distance between any two of said discrete areas does not exceed four inches.

12. The input device in accordance with claim 7 wherein the discrete areas are divided into a plurality of categories as a function of the characters represented thereby, and wherein the discrete areas are color-coded with a corresponding plurality of colors based on their respective category.

13. The input device in accordance with claim 7 wherein the discrete areas are divided into a plurality of categories as a function of theirlocation on the input device, and wherein the discrete areas are color-coded with a corresponding plurality of colors based on their respective category.

14. The input device in accordance with claim 7 wherein the input device comprises a keyboard and each of the discrete areas comprises a key, and wherein the keys are adapted to be activated by touching the stylus thereto.

15. The input device in accordance with claim 14 wherein the keyboard comprises a housing having one or more grooves, each groove cut into the housing between two of said keys for guided movement of the stylus therebetween.

16. The input device in accordance with claim 14 wherein the keyboard comprises a housing having one or more lights coupled thereto, each light associated with one or more of said keys.

17. The input device in accordance with claim 16 wherein the lights comprise light-emitting-diodes.

18. The input device in accordance with claim 16 wherein the plurality of keys includes a space key for separating sequences of one or more of said keys, and wherein one or more of the lights associated with keys in a givensequence of two or more keys is adapted to be illuminated when the given sequence of keys followed by the space key has been activated.

19. The input device in accordance with claim 16 wherein one or more of the lights associated with a given key is adapted to be illuminated whenthe given key has been activated.

20. A portable computing device comprising:

a housing;
a processor contained within the housing;
a display device electrically coupled to the processor; and an information input device adapted for input of English language text, the input device comprising a plurality of discrete areas representative of characters including the alphabetic letters A through Z, the discrete areas adapted to be activated by operatively coupling a stylus thereto, wherein the input device comprises at least eleven pairs of adjacent discrete areas, each of said pairs of adjacent discrete areas comprising areas representative of a pair of characters selected from the group consisting of E and R; I and N; H and T; I and T; A and T; E and T; N and O; A and N; E and S; A and R; E and N; O and R; E and H; E
and L; A and L; I and S; S and T; D and E; O and T; and C and E.

21. The portable computing device in accordance with claim 20 wherein the input device further comprises at least two triplets of discrete areas, each discrete area in each one of said triplets being adjacent to another discrete area in the one of said triplets, each of said triplets of discrete areas comprising areas representative of a triplet of characters selected from the group consisting of T, H
and E; I, O and N; I, N and G; A,N and D; T, I and O; E, N and T; and E, T and A.

22. The portable computing device in accordance with claim 20 wherein one or more of said characters are represented by more than one of said discrete areas.

23. The portable computing device in accordance with claim 20 wherein the discrete areas are arranged on the input device in a plurality of concentric geometric figures.

24. The portable computing device in accordance with claim 20 wherein the distance between any two of said discrete areas does not exceed fourinches.

25. The portable computing device in accordance with claim 20 wherein the discrete areas are divided into a plurality of categories as a function of the characters represented thereby, and wherein the discrete areas are color-coded with a corresponding plurality of colors based on their respective category.

26. The portable computing device in accordance with claim 20 wherein the discrete areas are divided into a plurality of categories as a function of their location on the input device, and wherein the discrete areas are color-coded with a corresponding plurality of colors based on their respective category.

27. The portable computing device in accordance with claim 20 wherein the input device comprises a keyboard and each of the discrete areas comprises a key, and wherein the keys are adapted to be activated by touching the stylus thereto.

28. The portable computing device in accordance with claim 27 wherein one or more grooves are cut into the housing, each groove cut into the housing between two of said keys for guided movement of the stylus therebetween.

29. The portable computing device in accordance with claim 27 further comprising one or more lights coupled to the housing, each light associated with one or more of said keys.

30. The portable computing device in accordance with claim 29 wherein the lights comprise light-emitting-diodes.

31. The portable computing device in accordance with claim 29 wherein the plurality of keys includes a space key for separating sequences of one or more of said keys, and wherein one or more of the lights associated with keys in a given sequence of two or more keys is adapted to be illuminated when the givensequence of keys followed by the space key has been activated.

32. The portable computing device in accordance with claim 29 wherein one or more of the lights associated with a given key is adapted to be illuminated when the given key has been activated.

33. A telecommunications device comprising:

a housing;

a microphone contained within the housing for converting acoustic signals to electrical signals for transmission through a telecommunications network;

a loudspeaker contained within the housing for converting electrical signals transmitted through the telecommunications network to acoustic signals; and an information input device adapted for input of English language text, the input device comprising a plurality of discrete areas representative of characters including the alphabetic letters A through Z, the discrete areas adapted to be activated by operatively coupling a stylus thereto, wherein the input device comprises at least eleven pairs of adjacent discrete areas, each of said pairs of adjacent discrete areas comprising areas representative of a pair of characters selected from the group consisting of E and R; I and N; H and T; I
and T; A and T; E and T; N and O; A and N; E and S; A and R; E
and N; O and R; E and H; E and L; A and L; I and S; S and T; D
and E; O and T; and C and E.

34. The telecommunications device in accordance with claim 33 wherein the input device further comprises at least two triplets of discrete areas, each discrete area in each one of said triplets being adjacent to another discrete area in the one of said triplets, each of said triplets of discrete areas comprising areas representative of a triplet of characters selected from the group consisting of T, H
and E; I, O and N; I, N and G; A,N and D; T, I and O; E, N and T; and E, T and A.

35. The telecommunications device in accordance with claim 33 wherein one or more of said characters are represented by more than one of said discrete areas.

36. The telecommunications device in accordance with claim 33 wherein the discrete areas are arranged on the input device in a plurality of concentric geometric figures.

37. The telecommunications device in accordance with claim 33 wherein the distance between any two of said discrete areas does not exceed fourinches.

38. The telecommunications device in accordance with claim 33 wherein the discrete areas are divided into a plurality of categories as a function of the characters represented thereby, and wherein the discrete areas are color-coded with a corresponding plurality of colors based on their respective category.

39. The telecommunications device in accordance with claim 33 wherein the discrete areas are divided into a plurality of categories as a function of their location on the keyboard, and wherein the discrete areas are color-coded with a corresponding plurality of colors based on their respective category.

40. The telecommunications device in accordance with claim 33 wherein the input device comprises a keyboard and each of the discrete areas comprises a key, and wherein the keys are adapted to be activated by touching the stylus thereto.

41. The telecommunications device in accordance with claim 40 wherein one or more grooves are cut into the housing, each groove cut into the housing between two of said keys for guided movement of the stylus therebetween.

42. The telecommunications device in accordance with claim 40 further comprising one or more lights coupled to the housing, each light associated with one or more of said keys.

43. The telecommunications device in accordance with claim 42 wherein the lights comprise light-emitting-diodes.

44. The telecommunications device in accordance with claim 42 wherein the plurality of keys includes a space key for separating sequences of one or more of said keys, and wherein one or more of the lights associated with keys in a given sequence of two or more keys is adapted to be illuminated when the givensequence of keys followed by the space key has been activated.

45. The telecommunications device in accordance with claim 42 wherein one or more of the lights associated with a given key is adapted to be illuminated when the given key has been activated.