New Interaction Techniques Department of Computer Sciences University of Tampere, Finland September – December, 2003 Grigori Evreinov Adaptive Scan Interval

in novel Wrist PDAs button functionality is a key question single-switch manipulation for text entry is also considered as a model for optimizing a menu selection task for physically challenged users scanning mode is one of accessibility options used in MS Windows system this mode was applied with onscreen keyboard to choose highlight areas by pressing a hot key or using a switch-input device Fossil Wrist PDA with Palm OS TAUCHI MMIG G. Evreinov 01_ Adaptive Scan Interval

TAUCHI MMIG G. Evreinov 02_ a performance with scan mode will depend on the congruence degree of user actions and the way of presenting spatial-temporal structure of the interface, while the feedback cues should play a role of strobe-signals to stimulate user behavior and to stabilize temporal framework for rhythmically-alternating cognitive and motor activities Adaptive Scan Interval recently diverse versions of the onscreen keyboards with a scanning option were designed to provide alternative access for people who cannot move any pointing device at all some of them are based on forecast and prediction of user behavior, auto- completion and phrase-based text entry phrase entry technique can be based on complicated asymmetric hierarchical structure with a huge number of branches to specify a phrase category [1, 2]

TAUCHI MMIG G. Evreinov 03_ Adaptive Scan Interval

TAUCHI MMIG G. Evreinov 04_ Adaptive Scan Interval

TAUCHI MMIG G. Evreinov 05_ Adaptive Scan Interval

TAUCHI MMIG G. Evreinov 06_ Adaptive Scan Interval a cyclic temporal sequence to simulate joystick’s state through a single switch operation by, when the right state appeared or was entered [2]

TAUCHI MMIG G. Evreinov 07_ Adaptive Scan Interval demo1 demo2 demo3 eLocutor [3]

TAUCHI MMIG G. Evreinov 08_ Adaptive Scan Interval in eLocutor [2], to type the sentence “what is the date today” took 6 clicks and 13 seconds after the first word was typed however, before the first word was typed it was necessary to pass 6 levels and make 6 clicks without any mistake this procedure can take 14 seconds or more depending on a number of alternatives on each used level branching with a huge number of alternatives makes difficult not the navigation itself but the waiting of the moment when a necessary menu item will be accessible (activated) another problem is: how to simulate “back step” or undo operation when the user can manipulate only a single button (switch)? that is, the problem is how to navigate and capture any item among the long menu list with maximal efficiency in any moment when only a single button is being used

[4] TAUCHI MMIG G. Evreinov 09_ Adaptive Scan Interval the problem of connectivity in complex cyclic menu can be decided through access hierarchy for key-nodes and short-cycles at the same time, if the system could individually and dynamically turn, scan mode could be more flexible real-time manipulation by scan-interval and adjustments of delays have been investigated by Simpson and Koester [4], Lesher et al. [5], and Bourhis [6]

TAUCHI MMIG G. Evreinov 10_ Adaptive Scan Interval Lesher et al. [5] developed a method for row-column scanning interface based upon quantitative measures of scanning performance the adjustment scheme optimized scanning delays after approximately 1200 selections (~240 words) [5]

TAUCHI MMIG G. Evreinov 11_ Adaptive Scan Interval Bourhis and Pino were built EDITH system based on mathematical model (MHP) of the operator’s behavior and statistical analysis of experimental data [6] a behavior model includes a particular sequence of actions, they are: perception, cognitive processing and motor actions T act = T p + T c + T m T p – perception cycle / period T c – cognition cycle T m – motion cycle T act – action times T act  T scan

T threshold selection highlighting the menu item TAUCHI MMIG G. Evreinov 12_ the temporal diagram of the algorithm for measuring the user performance through visual-motor reaction time and correction of the scan interval T 0 – the first variable interval, T 1 – the second variable interval and T 2 = T 1 T thresh. - dynamical threshold T thresh. = T 0 + T 1 Time T scan RT i T0T0 T2T2 T1T1 selection Adaptive Scan Interval in any case, physical stimulus starts the motor reaction that could be measured if the moment of stimulus is known based on real-time analysis the visual-motor reaction time, we can predict and optimize scan interval [ see too DwellTimeInteraction.ppt ]

TAUCHI MMIG G. Evreinov 13_ Adaptive Scan Interval Two examples in testing of the adaptive scan interval. Changing for T 0 – low graph; periodic correction for T1 and RTi – upper graph. one test phrase of six words could be enough to initialize the system, after this kind of calibration the proposed algorithm will automatically keep scan interval near convenient magnitude with given speed (increment dT) demo4

TAUCHI MMIG G. Evreinov 14_ Usability-testing software for… Adaptive Scan Interval [ see too T-Adaptive Unit in DwellTimeInteraction.ppt ]

TAUCHI MMIG G. Evreinov 15_ Private Sub ChangeScan() rTime > 100 or tScan / 2 Yes No ChangeScan ArrThresh(nClick) = tThresh ArrCThresh(nClick) = tThresh ArrScan(nClick) = tScan t1 = 0: t2 = 0 ArrThresh(nClick) = rTime - tScan nClick < (nAve + 1) Yes No ArrDTmp(nClick) = rTime - tScan aveThresh = tThresh Shift of array and count of the sliding aveThresh aveThresh < min lower limit Yes No aveThresh = min aveThresh < tThresh - tDelta aveThresh > tThresh + tDelta T0T0 Adaptive Scan Interval

TAUCHI MMIG G. Evreinov p 16_ aveThresh < tThresh - tDelta aveThresh > tThresh + tDelta tScan = tScan - tDelta sDelta = sDelta - tDelta ArrScan(nClick) = tScan tScan = tScan + tDelta sDelta = sDelta + tDelta sDelta > tIndex  tDelta sDelta < (-1)  tIndex  tDelta new current value tThresh = tThresh + CInt(sDelta / 2) sDelta = 0 tThresh = tThresh + CInt(sDelta / 2) sDelta = 0 tThresh < 50 tThresh = 50 lower limit ArrCThresh(nClick) = tThresh new current value Private Sub ChangeScan() tScan < 100 tScan = 100 lower limit Adaptive Scan Interval change Line2 position change Line1 position

TAUCHI MMIG G. Evreinov 17_ Adaptive Scan Interval txtEntry_1Btn_a Usability-testing software for…

TAUCHI MMIG G. Evreinov 18_ Adaptive Scan Interval Start Click imaging the 1 st active group of menu items imaging the 2 nd active group of menu items imaging the 3 d active group of menu items the First Click changing content of the group Start Click the 1st Click the 2nd Click the 3d Click ERA DHL GWV TIS CFP BXK NO_ UMY QJZ ERA DHL GWV TIS CFP BXK NO_ UMY QJZ ERA DHL GWV E R A E Time

TIS CFP BXK NO_ UMY QJZ ERA DHL GWV TAUCHI MMIG G. Evreinov 19_ Adaptive Scan Interval Press-and-hold the key Up the 2nd Click ERA DHL GWV E Time E R A E TIS CFP BXK NO_ UMY QJZ ERA DHL GWV Press-and-hold the key Up ERA DHL GWV Time E R A Cancel BackSp Signs Stop Edit File TextEntry Text entry will be switched into commands selection mode

TAUCHI MMIG G. Evreinov 20_ Adaptive Scan Interval average times (and standard deviation) needed to choose any character at scan interval 460 ms regarding to predicted values (the left columns) summarized relative frequency of the characters per one thousand letters used during the test for each group (according to accessibility) is shown in the bottom

TAUCHI MMIG G. Evreinov p 21_ References [1] File, P., Todman, J., Higginbotham, J., Lesher, G.W., Moulton, B.J., Alm, N. CONTACT: A Communication Aid Based on Pre-Prepared Phrases. AAATE’03, Contact_146-final.pdf [2] Seveke, E. & Seveke, L. Computer aids for handicapped persons (MauSi scan). fuer-behinderte.de/ fuer-behinderte.de/ [3] Mehta, A. eLocutor version 2. [4] Simpson, R.C., Koester, H.H. Adaptive one-switch row-column scanning. IEEE Transactions on Rehabilitation Engineering 7(4), (1999), [5] Lesher, G.W., Higginbotham, D.J., and Moulton, B.J. Techniques for automatically updating scanning delays. Proc. of the RESNA 2000, (2000), Available at: [6] Bourhis, G., Pino, P. Temporal analysis of the use of an augmentative communication device. Proc. AAATE’03. IOS Press, Netherlands (2003), [7] Specialized Input Systems. Onscreen keyboards. Assistive Technology Training Online Project, [8] Stephanidis, C., Savidis, A. Interface development toolkits for non-visual and switch-based interaction. Proc. ERCIM News, Special Theme: Human Computer Interaction, 46 (2001, July) Adaptive Scan Interval