CHAPTER 6 Conclusions and Future Works
6.2 Implications
6.1 Conclusions
D3 on-screen keyboard provides both direct selection methods and indirect selection methods. Users could use D3 on-screen keyboard with suitable assistive devices, selection methods, layout arrangements, and layout sizes when his/her ability of motor control changed. The presented sample of diverse participants illustrated motor-challenged users could benefit from D3 on-screen keyboard. Based on the findings of the experiment, two general conclusions can be drawn:
1. The individuals with motor disabilities could use D3 on-screen keyboard with minimal requirement of training.
2. With appropriate intervention, D3 on-screen keyboard is an effective text entry system for person with severe motor disabilities.
To provide proper computer access solutions for persons with motor disabilities, assistive system must address many factors reflecting the diverse requirements of physically challenged individuals and their dynamic degeneration of physical abilities.
without lots of efforts. Although the current version of D3 on-screen keyboard are robust deployable prototypes, there is still room to improve it. Four suggestions for future work have been identified based on the comments provided by the participants, teachers and therapists.
1. Embedding automatic detection mechanism. To support an individual with
adaptable access method and customization is often a cumbersome process— not only do clinic professionals face the complex task of manually evaluating the user’s performance and adjusting the configuration setting, motor-challenged users are burdened with the work of investigating and activating the relevant features in the existing set of the text entry system. Therefore, to ease users’ burden, automated and focused support for configuration will become necessary when the flexible configurations increased. Moreover, in order to assist individuals in their efforts to identify and activate relevant configuration facilities, some mechanism for recognizing a user’s performance is desirable. D3 on-screen keyboard can of great use to users since it could embed the auto detection function which could record the user’s performance and then accordingly provide the adjustment suggestions. The current text entry system provides a layout adaptation evaluation program for the professionals to set up suitable configurations for their clients. However, for users to work more independently, the text entry system could integrate an automatic
configuring mechanism to detect suitable configurations when the users interact with computer.
2. Designing enhanced options for specific applications. The graphical user interface
(GUI) is becoming the standard computer interface and severe motor-disabled users who can only use an on-screen keyboard find difficulty in operating the buttons on the menu bar in GUI environments. Rather than moving the cursor to the target icons, such a user could click a key on the macros layout to execute the specific functions. For instance, the user could print the document with just one stroke. On the other hand, letter-by-letter spelling is a slow process and an inefficient method for the generation of text, especially for individuals with upper limb motor disabilities. The results of the previous research (Anson, et. al, 2006; Tam, Reid, Naumann, & O’Keefe, 2002) showed that the use of word prediction may assist users to improve typing speed. The module of word prediction could be embedded to the typing system to enhance the performance.
3. Including voice command in numeric coded selection method. The need for
entering text has driven numerous inventions in text entry in recent years. Speech recognition has been expected to be a good alternative text entry method; however, previous study (Karat, Halverson, Horn & Karat, 1999) indicated that the effective speed of text entry by speech recognition was still far lower than that of the
keyboard, especially for error correction task. For users with severe motor disabilities, but yet with good speech capability, the voice command mode may be an alternative solution for text entry task. They could use ten different voice commands, serving as number 0 to number 9, to operate the numeric coded selection method.
4. Integrating to augmentative alternative communication systems. The
augmentative alternative communication (AAC) systems have been used by various groups with complex communication needs, from developmental to acquired disabilities; groups of both young children and older adults. The goal of AAC is essential in maximizing functional communication, enhancing language development, and promoting learning for disabled person with complex communication needs. The primary purpose of this study is to enhance text entry by an innovative on-screen keyboard for people with disabilities. Writing is one of the major domains of AAC. Entering text by picture interface may be more effective for people with dyslexia. The future version of D3 on-screen keyboard can embed the picture communication symbols (PCS) to develop the picture layout to help dyslexic users to write. Additionally, persons with aphasia could also use D3 keyboard to communicate with other people.
6.2 Implications
The use of assistive technology in rehabilitation has the potential to enable the students with severe motor disabilities to have greater ease in accessing computer, or augmenting communication. Mainstream system design could only of use to able-bodied users. It is possible for accessibility features being offered as part of some mainstream system, but the idea of designing for dynamic diversity is not being emphasized. The designing of some assistive system respond to the need of diversity for some potential user population, but it ignores the user’s dynamic needs. Based on the idea of designing for dynamic diversity, four implications appear warranted.
The most important implication is that successful computer access for a specific user requires a combined approach. Assessing the individual special needs is not only aimed to support an alternative input device, but should develop an appropriate intervention and training with regard to the individual’s environment. Furthermore, the intervention and training should open up new learning opportunities for the individuals. Only one evaluation session can only take a point of the individual’s abilities at that time and the abilities will change through maturing, developing and learning over time.
As shown in Figure 6-1, supporting an appropriate assistive technology for
for monitoring and controlling the assistive system to ensure that the system suits the individual’s skills and needs. Furthermore, a follow-up and follow-along intervention is necessary. Follow-along is carried out over the user’s lifetime. Users may need advanced service or information of the assistive system after a period of learning.
Change of the user’s profile can also be the result of a degenerative condition.
A team approach is suggested when accessing an appropriated text entry system for disabled persons. The assessment and intervention processes often require specialists in occupational therapy, special education, information education, computer engineering, electronic engineering, and so on.
Figure 6-1 The cycle of intervention
Second, the results of this study indicate that there is no single best access option for all persons with disabilities. Standard keyboard is preferred by most disabled persons due to the fact that standard equipment is cheap, faster, and less complex. For the assessment process, direct selection should be evaluated first. If direct selection is impossible, or if it is too tiring for the individual, then indirect selection methods are recommended. Coded selection method is recommended for individuals who have good memory skills. The novice users need to have extensive practice and training before they could use a chord input system. This study suggested that coded selection method could be improved to reduce the learning demands for users by employing the visual cueing strategy.
Third, the performance measures in this study involve speed and accuracy.
However, a good text entry system for persons with motor disabilities has many desired dimensions. Besides the efficiency, the following three criteria are required.
1. It should have a rapid learning curve.
2. It should impose a lower cognitive and perceptual demand on the user.
3. It should be easy to access.
Finally, with the increasing recognition of the important of special needs in system design, universal design is being promoted in information technology and it is one of the essential concepts in system development. However, universal accessibility based
on the traditional understanding of disability is given only on the start point. In addition to the diversity of the users, the assistive technology needs to reflect the broadest range of users’ situations circumstances. Designing for dynamic diversity requires that researchers and designers consider all potential user groups of systems.
The assistive system must include a variety of multiple solutions to meet the individual’s needs and supports flexible options for an individual’s needs dynamically.
6.3 Limitations of This Study
Generalization of the results from this study should be viewed with caution for five primary reasons. Firstly, all participants had QWERTY keyboard or QWERTY layout experience. Therefore, the results may not be applied to individuals with little or no keyboarding skills. However, the author believes that most individuals who rely on computer access assistive technology have been exposed to keyboarding early, and have used keyboards or control interfaces for a variety of educational and daily activities. Secondly, this study focused on the motor operation performance of the two devices by reducing the difficulty to a copying task of a target English character. Whereas the simple task allowed us to explore the operational issues and procedures for comparing two devices, the results may not always reflect real-world situations. Thirdly, due to the small size of the
participants, the finding of this study should not be generalized to persons with other types of motor disabilities. Fourthly, human-computer design of use speed and accuracy as measures of motor performance. However, several variables may affect the performance, such as cognition, degree of fatigue, and users’ control site.
More studies are needed to identify which factors predominantly affect the text entry task.
Finally, the participants were evaluated in English characters only; the findings of this study may be restricted when Chinese text entry methods are applied.
6.4 Suggestions for Future Research
The results of this study leads to four suggestions for future exploration of the text entry system for persons with motor disabilities.
1. Replication of this study on subjects diagnosed with other types of disabilities is recommended, such as person with spinal cord injury, brain injury or visual impairment. Replication this study on subjects who use on-screen keyboard would help determine the efficiency of different computer access options. As illustrated in the above research design, in each session, the participants were only given five minutes for practicing and ten minutes for evaluation D3 on-screen keyboard. It
real natural daily activity of text entry. Whether participants’ fatigue may be a potentially confounding variable that will affect performance must be evaluated in future studies.
2. Speed and accuracy of movements was used to evaluate the participants’
performance in this study. The result indicated that after few sessions of practice, all of the participants reported higher speed of D3 on-screen keyboard than their original text entry methods in the end of the comparison phase. In general, speed and accuracy are inversely related. The relationship between these to parameters is also affected by the level of experience the user has. For a novice, the relationship illustrated above holds. However, for experienced users, increasing speed does not necessarily result in decreased accuracy. A further long-term exploration of the user performance is suggested.
3. In additional to basic operational competence, it is necessary for the user to develop strategies that maximize the effectiveness of the text entry system. Further studies need to be undertaken to investigate the performance of using the proposed text entry system with other specific devices and training strategies. In advance, it is important for designers and educators to rethink and reinvent the better accessibility e-Learning environment from the designing for dynamic diversity perspective.
4. The experimental task conducted in this study focused on the typing target
characters displayed on the screen only. It required little of the participants’
cognitive and language skills. Although the experiment design was simplified and well demonstrated the system design, simply typing the assigned characters was not functional enough for a learner on entry text in the learning activities. Since this study illustrated the effect of the coded selection method with visual strategies on typing the assigned target characters, the future study could further develop a text entry training program and explore the effect of text entry more functionally. For example, explore the quality of the article writing or online discussion.
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