Improving Text Entry Performance for Spanish-Speaking Non-Expert and Impaired Users

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1 Improving Text Entry Performance for Spanish-Speaking Non-Expert and Impaired Users Francesco Curatelli Chiara Martinengo University of Genova, Italy Oscar Mayora-Ibarra ITESM, Cuernavaca, Mexico October 23-26, 2005 CLIHC 2005 Cuernavaca, Mexico

it Chiara Martinengo martinen@dima.unige.

2 Outline Motivation Pseudo-syllabic text entry method Orthogonal keyboard Method evaluation Conclusions October 23-26, CLIHC 2005 Cuernavaca, Mexico

3 Computers have become the main tool for increasing the productivity in most human activities; but Most people do not acquire enough fluency in typing Non-expert users: lack of training and continuous use Motor-impaired users: severe physical movement and visual exploration constraints Very low typing speeds: Non-expert users: few CPS (Characters per second) Motor-impaired users: typically less than 1 CPS Solution: designing new text entry interfaces that be: more efficient (higher CPS) AND also tailored to user s native language Motivation October 23-26, CLIHC 2005 Cuernavaca, Mexico

typing speeds: Non-expert users: few CPS (Characters per second) Motor-impaired users: typically less than 1 CPS Solution: designing new text entry

4 Motivation Keyboards: SW (mouse, pen, ) or HW (one-finger typing) Choice selection time (non-expert users) Hick-Hyman law T ν = a + b log 2 ( n) n number of possible selections a starting time (0 for continuous text entry) 1/b bandwidth [bits/sec] (the rate at which choices are processed) For non-expert users: T ν = 0.2 log 2 ( n) Movement latency time (motor-impaired users) Fitts' law model:t λ = a + b log 2 ( d/w + 1) d distance between two consecutive keys w the width of the keys a, b empirical constants (to be set according to the users class) T ν &T λ put strict upper bounds on #keys /sec October 23-26, CLIHC 2005 Cuernavaca, Mexico

2 log 2 ( n) Movement latency time (motor-impaired users) Fitts' law model:t λ = a + b log 2 ( d/w + 1) d distance between two consecutive keys w the width of the

5 Pseudo-syllabic text entry method Goal: achieving best typing speed by: lowering KSPC (keystrokes per character) as much as possible providing a more intuitive access method lowering choice selection time lowering movement latency time Basic idea: pseudo-syllabic text entry units Target: alphabetic language L with transparent orthography G = ( g 1... g m ) sequence of graphemes, g i L P = ( p 1... p n ) sequence of phonemes, g i L Each grapheme is denoted by one or more alphabetic letters L is completely transparent if g i p j for any g i L L is almost transparent if g i [g]* p j [p]* for any g i L Most languages in the world are almost transparent languages! October 23-26, CLIHC 2005 Cuernavaca, Mexico

.. g m ) sequence of graphemes, g i L P = ( p 1.

6 Pseudo-syllabic text entry method Pseudo-syllables (p-syllables): strict subset of the language syllabic set. Table: frequencies of the consonant-vowel syllables structures in Spanish [Just96] Justicia, F., et al. La frecuencia silábica del español escrito por niños: estudio estadístico. Cognitiva 8 (1996), C V is definitively the most frequent syllable structure V and V C are frequently occurring too Typical of most languages! N Type % N Type % 1 CV 53,37 2 CVC 20,41 3 V 7,79 4 VC 6,52 5 CVV 4,93 6 CCV 3,48 7 CVVC 2,10 8 CCVC 1,13 9 CVVV 0,07 10 VV 0,05 11 CVVVC 0,05 12 CCVV 0,04 13 CCVVC 0,02 14 CVCC 0,02 15 VVC 0,01 16 VCC 0,00 October 23-26, CLIHC 2005 Cuernavaca, Mexico

La frecuencia silábica del español escrito por niños: estudio estadístico. Cognitiva 8 (1996), 131-168.

7 Orthogonal keyboard Goal: keyboard framework such that non-expert users: are able to fast access any possible p-syllable in the keyboard by exploiting a limited amount of knowledge about a keyboard layout of reduced size Proposed solution: Orthogonal Keyboard Keyboard: N x x N y rectangular array of keys, N x = CS* L, N y = VW* L All the keys with the same consonant grapheme are allocated onto the same keyboard column. All the keys with the same vowel grapheme are allocated onto the same keyboard row. Rows and columns are lexicographically ordered (ε first) Forward/reverse shift (FR-Sh) is used to select one of the two p-syllables mapped to the same keyboard key (default: C* V*). b c d f g h j k l m n p q r s t v w x y z a ba ab ca ac da ad fa af ga ag ha ah ja aj ka ak la al ma am na an pa ap qa aq ra ar sa as ta at va av wa aw xa ax ya ay za az e be eb ce ec de ed fe ef ge eg he eh je ej ke ek le el me em ne en pe ep qe eq re er se es te et ve ev we ew xe ex ye ey ze ez i bi ib ci ic di id fi if gi ig hi ih ji ij ki ik li il mi im ni in pi ip qi iq ri ir si is ti it vi iv wi iw xi ix yi iy iz zi o bo ob co oc do od fo of go og ho oh jo oj ko ok lo ol mo om no on po op qo oq ro or so os to ot vo ov wo ow xo ox yo oy oz zo u bu ub cu uc du ud fu uf gu ug hu uh ju uj ku uk lu ul mu um nu un pu up qu uq ru ur us su tu ut uv vu uw wu xu ux uy yu uz zu FR-Sh October 23-26, CLIHC 2005 Cuernavaca, Mexico

the same keyboard column. All the keys with the same vowel grapheme are allocated onto the same keyboard row.

8 Orthogonal keyboard L : hypothetical completely transparent language, with only C*V* and V*C* syllables: CS* sp = {ε, b, c, d, f, g, h, j, k, l, m, n, p, q, r, s, t, v, w, x, y, z}, CS* L = 22 VW* sp ={ε, a, e, i, o, u}, VW* L = 6 FR-Sh OFF. b c d f g h j k l m n p q r s t v w x y z a ba ca da fa ga ha ja ka la ma na pa qa ra sa ta va wa xa ya za e be ce de fe ge he je ke le me ne pe qe re se te ve we xe ye ze i bi ci di fi gi hi ji ki li mi ni pi qi ri si ti vi wi xi yi zi o bo co do fo go ho jo ko lo mo no po qo ro so to vo wo xo yo zo u bu cu du fu gu hu ju ku lu mu nu pu qu ru su tu vu wu xu yu zu Let us write the syllable ca : orthogonal composition of c and a Reduced knowledge and cognitive load! October 23-26, CLIHC 2005 Cuernavaca, Mexico

b c d f g h j k l m n p q r s t v w x y z a ba ca da fa ga ha ja ka la ma na pa qa ra sa ta va wa xa ya za e be ce de fe ge he je ke le me ne pe qe re se te ve we xe ye ze i bi ci di fi gi

9 Orthogonal keyboard October 23-26, CLIHC 2005 Cuernavaca, Mexico

10 Orthogonal keyboard Optimisation steps to reduce the keyboard size Column deletion (CD) Row deletion (RD) Column folding (CF) selection shift: CF-Sh Row folding (RF) selection shift: RF-Sh Column merging (CM) For Spanish keyboard: Reduce the vertical size by folding each vowel row with the accented vowel one ( a á) ( e é ) ( i í ) ( o ó) ( u ú) N x = 27, N y = 6 October 23-26, CLIHC 2005 Cuernavaca, Mexico

(CM) For Spanish keyboard: Reduce the vertical size by folding each vowel row with the accented vowel

11 Orthogonal keyboard FR-Sh OFF RF-Sh OFF. b c ch cu d f g h j k l ll m n ñ p qu r rr s t v w x y z a ba ca cha cua da fa ga ha ja ka la lla ma na ña pa qua ra rra sa ta va wa xa ya za e be ce che cue de fe ge he je ke le lle me ne ñe pe que re rre se te ve we xe ye ze i bi ci chi cui di fi gi hi ji ki li lli mi ni ñi pi qui ri rri si ti vi wi xi yi zi o bo co cho cuo do fo go ho jo ko lo llo mo no ño po quo ro rro so to vo wo xo yo zo u bu cu chu cuu du fu gu hu ju ku lu llu mu nu ñu pu quu ru rru su tu vu wu xu yu zu KSR α = 100 (1 KSPC α ) Keystoke saving rate (alphanumeric) arte: ar-te KSR α = 50% español: es-pa-ño-l KSR α 43% llave: lla-ve KSR α = 60% americano: a-me-ri-ca-no KSR α 44% October 23-26, CLIHC 2005 Cuernavaca, Mexico

ne ñe pe que re rre se te ve we xe ye ze i bi ci chi cui di fi gi hi ji ki li lli mi ni ñi pi qui ri rri si ti vi wi xi yi zi o bo co cho cuo do fo go ho jo ko lo llo mo no ño po quo ro

12 Method evaluation The orthogonal keyboard, extended with non-alphanumeric keys, has been tested by tracing the following parameters: word char alpha other space sh shsel alphak KSPCα KSPCγ KSRα KSRγ total number of words; = (alpha + other) : total number of characters; total number of alphanumeric characters; total number of non-alphanumeric characters; total number of space characters; total number of capital letter shifts; total number of FR, RF, and CF shifts; total number of alphanumeric keys in input; = (alphak/alpha) : alphanumeric keystrokes per character; = (alphak + other)/(char) : keystrokes per character; = 100 ( 1 - KSPCα ) : alphanumeric keystroke saving rate; = 100 ( 1 - KSPCγ ) : keystroke saving rate. October 23-26, CLIHC 2005 Cuernavaca, Mexico

characters; total number of capital letter shifts; total number of FR, RF, and CF shifts; total number of alphanumeric keys in input; = (alphak/alpha) : alphanumeric keystrokes per character; =

13 Experiment 1 - simulation Method evaluation Automatic acquisition of text files (ABC and El Día articles) Text word char alpha other space sh shsel alphak abc abc eldia eldia Text KSPC α KSR α KSPC γ KSRγ abc-1 0, ,37 0, ,22 abc-2 0, ,73 0, ,12 eldia-1 0, ,74 0, ,65 eldia-2 0, ,93 0,644 35,59 October 23-26, CLIHC 2005 Cuernavaca, Mexico

6522 5873 3888 18440 eldia-2 5748 34900 28274 6626 5691 5088 3475 15851 Text KSPC α KSR α KSPC γ KSRγ abc-1 0,5662 43,37 0,6577 34,22 abc-2

14 Method evaluation Experiment 2 non-expert Spanish-speaking users Spanish hardware orthogonal keyboard vs qwerty keyboard Modular programmable keyboard, x-y matrix layout, and long travel key switches Four people, aged 30 to 50 T Q, T S WPM Q, WPM S %Gain total times (sec) for qwerty and orthogonal keyboards words per minute for qwerty and orthogonal keyboards % gain in using the orthogonal keyboard User T Q T S WPM Q WPM S %Gain User ,14 11,63 42,84 User ,54 9,38 43,42 User ,89 12,18 54,37 User ,18 10,73 49,47 October 23-26, CLIHC 2005 Cuernavaca, Mexico

keyboards words per minute for qwerty and orthogonal keyboards % gain in using the orthogonal keyboard User T Q T S WPM Q WPM S %Gain User 1 3317 2322

15 Experiment 1 Method evaluation KSR α [43.37%, 43.93%] KSR γ [34.22%, 35.65%] Comparable with best prediction tools (single word prediction) Experiment 2 No previous training with orthogonal keyboard! %Gain values quite better than the KSR γ s obtained in Experiment 1 In fact, for non-expert users: 1. Orthogonal keyboard provides intuitive and fast row + column access to the key position; 2. Qwerty keyboard requires a significantly higher choice selection time to locate keys that are placed randomly on the keyboard layout For impaired users, experiments are much more difficult, but a limited preliminary and the considerations 1., 2. suggest that similar gains can be obtained October 23-26, CLIHC 2005 Cuernavaca, Mexico

%Gain values quite better than the KSR γ s obtained in Experiment 1 In fact, for non-expert users: 1.

16 Conclusions Cumulative gains in terms of KSR can be obtained by adding: Word completion and prediction Automatic space insertion Intelligent phrase understanding Future work: Specific validation for impaired users Optimized hardware and software keyboards Application of the orthogonal framework to other transparent languages (already available for Italian) Extension of the p-syllable model to characterize more complex syllables structures October 23-26, CLIHC 2005 Cuernavaca, Mexico

software keyboards Application of the orthogonal framework to other transparent languages (already available for Italian)

1.- L a m e j o r o p c ió n e s c l o na r e l d i s co ( s e e x p li c a r á d es p u é s ).

1.- L a m e j o r o p c ió n e s c l o na r e l d i s co ( s e e x p li c a r á d es p u é s ). PROCEDIMIENTO DE RECUPERACION Y COPIAS DE SEGURIDAD DEL CORTAFUEGOS LINUX P ar a p od e r re c u p e ra r nu e s t r o c o rt a f u e go s an t e un d es a s t r e ( r ot u r a d e l di s c o o d e l a