Chen, M.C. and Hill K.J., Redesign of a Keyboard Layout to Enhance the Proficiency of Text-entry for Single Digit Mandarin Chinese Users. Paper presented at the 2008 Clinical AAC Research Conference, Charlottesville, VA.
Redesign of a Keyboard Layout to Enhance the Proficiency of Text-entry for Single Digit Mandarin Chinese Users 1
Ming Chung Chen1 and Katya Hill2 National Chiayi University (Taiwan); 2University of Pittsburgh
Abstract: This study aimed to design a Mandarin Chinese (MC) alternative keyboard layout for the single digit typist. An alternative 6 rows * 7 columns keyboard layout was created to compare performance with the standard MC keyboard layout. Principles of human computer interaction were used in designing the alternative keyboard. The alternative keyboard was compared with a standard keyboard in an experiment involving the collection of performance data from three adolescents with quadriplegia. The participants performed faster and more accurately when using the alternative MC keyboard configuration than when using the QWERTY-type layout. Suggestions for future research based on the findings of this pilot project are proposed.
Research Description Enhancing communication rate is one of the essential issues in the Augmentative and Alternative Communication (AAC) assistive technology field. Techniques and strategies designed to enhance performance for the generation of either written and oral utterances require systematic and scientific data collection to build evidence for decision making (Hill, 2006). With the growth of information technology in Taiwan, the application of assistive technology for written communication has gained acceptance and popularly. Consequently, evaluating the performance of technologies designed specifically for written communication becomes important for decision-makers matching persons with technology (Scherer, Jutai, Fuhrer, Demers, & DeRuyter, 2007). An appropriate text-entry system can decrease the barriers of typing with a computer and enhance the efficiency of text entry (Cook & Polgar, 2008), especially for the people with severe upper extremity impairments. An appropriate keyboard layout is essential for single-digit typists to enter text efficiently. Numerous researchers have engaged in designing English keyboard layouts for the typist with upper extremity impairments (Kroemer, 1999). LIAISON and Chubon keyboards are two of the most conventionally adopted ones (Chubon & Hester, 1988; Cook, Polgar, 2008; Hurlburt & Ottenbacher, 1992). However, could the principles of alternative keyboard layout design adopted by Chubon and Hester (1988) also be used to design an alternative Mandarin Chinese (MC) keyboard layout? In addition to layout design, selecting an adapted input method is another important issue for typists who use Chinese (Chen, 2000). Different from the spelling system, there are several methods for typing MC characters on the computer. Two major types of
Mandarin Chinese input methods are used in Taiwan. One is the phonic-coding input method (Pinyin), and the other is the pattern-coding input method to produce a Chinese character. When using Pinyin method, the typist needs to press the phonetic symbols of the character in proper order, and then the computer displays the homonyms. On the other hand, the typist needs to assemble the necessary partials/roots in correct sequence to generate a character when using a pattern-coding method. Research in this study chose the Da-Yi input method, a pattern-coding input, to design the keyboard layout, because of its effectiveness and ease of learning for individuals even with cognitive disabilities (Chen, 2000; Chen, Wang, & Chen Wang, 2000). This study aimed to design a MC Da-Yi alternative keyboard layout for the single-finger typist, and to evaluate the efficiency of the new keyboard layout. Alternative Keyboard Layout Design A common MC word database from the Ministry of Education in Taiwan (1998) was used to calculate the frequency of each MC character. The top 641 characters that represented 80% of the frequency of the total 1,579,771 characters were used to decode into Da-Yi roots. The Da-Yi root frequencies were used to evaluate the existing keyboard and support the design of the alternative keyboard. The alternative keyboard layout rearranged each root based on the frequency analysis taking into consideration the principles of designing an alternative keyboard (Chubon & Hester, 1988). The major principles considered included: 1) centralizing the most commonly used roots, 2) adjoining the roots that were most frequently used together in a close proximity, 3) putting the roots that tend to be used as a prefix on the left side of the keyboard layout, and those that were used as a suffix on the right side. The standard and the alternative keyboard layouts are shown in Figure 1.
Figure 1.Shows both keyboard layouts. The left represents the alternative keyboard, and the right shows the Da-Yi roots on the standard keyboard. Note: Represent primary area Represent secondary area
Methods Participants Three participants (1 female and 2 males), aged 17, were involved in the evaluation of the two keyboard configurations. Table 1 shows the background of the participants.
Table 1 Characteristics of the three participants Participants Disabilities
WISC-III TONI** Difficulties in (Verbal)* adaptive skills A Quadriplegia(CP) 73 114 Oral expression is not very clear. B Quadriplegia(CP) 65 71 Oral expression is not very clear. Some problems in academics. 57 75 Some problems in C Quadriplegia(CP) academics. *: Wechsler Intelligence Scale for Children-III. **:Test of Nonverbal Intelligence-II, a nonverbal IQ test.
Typing technique Left hand Thumb Left hand Forefinger
Typing performance Phonic input 8/WPM Phonic input 2/WPM
Right hand Phonic input Thumb 2/WPM
Experimental materials and apparatus A laptop computer with PENTIUM- 500 CPU and a 12 inch screen was used to conduct the evaluation task in a counseling room at the dormitory in the school in Taiwan. A software application was programmed using Visual BASIC 6.0 to have the Da-Yi roots appear on the screen one at a time and disappear when the subject selected the root on the keyboard. The Da-Yi keyboard layout was implemented on an adaptive computer interfaced of Unlimiter-1 system (U1) (Assistive Technology Engineering Lab, 1999), a type of programmable membrane keyboard that is used to edit specific keyboard overlays. The size of a key was 1.2 cm for height; 1.0 cm for width and the interval between the two keys was 1.0 cm. Experiment design An Alternating treatment design (ATD) within-subject design was employed to explore the efficiency of the new layout. The independent variable is the type of keyboard layout: 1) the QWERTY layout with Da-Yi roots, 2) the alternative layout with Da-Yi roots. The dependent variables are speed and accuracy of the key selections for root pressing. The accuracy (%) was calculated by the formula: (number correct roots)/( number correct roots + number uncorrect roots) x 100. The speed was defined as the number of the correct roots typed in the five minutes. The experiment consisted of three phases: Preparing phase. The participants were introduced to the task and the evaluation procedure a few days before the individual evaluation. They were taught to operate the evaluation program. Comparison phase. Researchers randomly selected the target roots to run with the evaluation program and randomly assigned the order of the keyboard to be used by the subjects. The participants took the evaluation after a two minute practice. The target root appeared on the screen and he/she was requested to press the corresponding key on the keyboard. The next root automatically appeared after a selection. The program recorded the key that was pressed and the time spent. After the first evaluation session the subject was allowed a break before the next evaluation on the other keyboard. The number of correct key presses in 5 minutes was counted, and the evaluation was terminated once 100 roots were reached. Final phase. The participants used the keyboard layout with their best performance in the final phase only.
Amount of correct stroke
Results Figures 2, 3, and 4 show the results of each participant for the speed and accuracy achieved during the evaluation procedures. Speed of key pressing. All the participants reached the criterion. In additional, Participants A and C improved their speed performance in the final phase. Accuracy of key pressing. Accuracy was improved for both layouts with trials. Social Validation. Researchers asked the subjects how they felt during the evaluation and which keyboard layout they preferred. All the participants indicated that the alternative keyboard was easier to use.
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Figure 2. Correct keystrokes and accuracy rate for subject A
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Figure 3. Correct keystrokes and accuracy rate for subject B
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Figure 4. Correct keystrokes and accuracy rate for subject C
Summary This experiment explored an alternative keyboard configuration to identify whether modifications to the organization of Da-Yi roots would influence speed and accuracy in performance. The pilot results are promising in demonstrating that improvements to the standard QWERTY layout for accessing Da-Yi roots to produce characters may lead to faster and more effective keyboards for individuals with disabilities wanting to generate either written or augmentative and alternative communication (AAC). These early results show the need to refine the experimental procedures by developing and using tools that will more accurately measure (record) the time and events required for generating written MC or other graphic character (symbol)-based languages. Specifically, differentiating and defining measures and formulas for reporting communication rate as well as selection rate are imperative in order to compare results among studies. Future research
can then be conducted on larger within-subject and between-subject designs manipulating and targeting various independent variables under consideration. References Assistive Technology Engineering Lab (1999). Unlimiter-1 (U1) system. Taipei: Assistive Technology Engineering Lab. Chen, M. C. (2000). The study of teaching individuals with mental retardation to learn Da-Yi input method. Bulletin of Special Education, 19, 195-214. Chen, M. C., Wang, H. P., & Wang-Chen, L. C. (2000). Research on teaching Da-Yi Chinese keyboarding by using adaptive input interface. Proceedings of International Conference on Computers in Education, Taipei, 8, 535-541. Chubon, R. A., & Hester, M. R. (1988). An enhanced standard computer keyboard system for single-finger and typing-stick typing. Journal of Rehabilitation Research and Development, 25(4), 17-24. Cook, A. M., & Polgar, J. M. (2008). Cook and Hussey’s assistive technologies: Principles and practice.(3rd Ed.). Baltimore: Mosby. Department of Education in Taiwan (1998). The report of common words surveyed in 1998. Taipei: Department of Education. Hill, K. (2006). Augmentative and alternative communication (AAC) research and development: The challenge of evidence-based practice. International Journal of computer processing of oriental language. 19(4), 1-14. Hurlburt, M., & Ottenbacher, K. J. (1992). An examination of direct selection typing rate and accuracy for persons with high spinal cord injury using QWERTY and default on-screen keyboards. Journal of Rehabilitation Research and Development, 29(4), 54-63. Kroemer, K. H. E. (2001). Keyboards and keying: An annotated bibliography of the literature from 1878 to 1999. Universal Access in the Information Society, 1, 99-160. Scherer, M., Jutai, J., Fuhrer, M., Demers, L. & DeRuyter, F. (2007). A framework for modeling the selection of assistive technology devices (ATDs). Disability and Rehabilitation: Assistive Technology, 2(1), 1-8.
Contact Ming Chung Chen Associate Professor National Chiayi University 300 Syuefu Rd. Chiayi, Taiwan 600 Tel: 412-251-3583 FAX: 412-383-6555 E-mail:
[email protected]
