• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.149-155
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• 2007

Recently, various devices requiring text input such as mobile phone IPTV, PDA and UMPC are emerging. The frequency of text entry for them is also increasing. This study was focused on the evaluation of Korean text entry interface. Various models to evaluate text entry interfaces have been proposed. Most of models were based on human cognitive process for text input. The cognitive process was divided into two components; visual scanning process and finger movement process. The time spent for visual scanning process was modeled as Hick-Hyman law, while the time for finger movement was determined as Fitts' law. There are three questions on the model-based evaluation of text entry interface. Firstly, are human cognitive processes (visual scanning and finger movement) during the entry of text sequentially occurring as the models. Secondly, is it possible to predict real text input time by previous models. Thirdly, does the human cognitive process for text input vary according to users' text entry speed. There was time gap between the real measured text input time and predicted time. The time gap was larger in the case of participants with high speed to enter text. The reason was found out investigating Eye-Hand Coordination during text input process. Differently from an assumption that visual scan on the keyboard is followed by a finger movement, the experienced group performed both visual scanning and finger movement simultaneously. Arrival Lead Time was investigated to measure the extent of time overlapping between two processes. 'Arrival Lead Time' is the interval between the eye fixation on the target button and the button click. In addition to the arrival lead time, it was revealed that the experienced group uses the less number of fixations during text entry than the novice group. This result will contribute to the improvement of evaluation model for text entry interface.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.259-264
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• 2011

Does preferred hand show better performance than non-preferred hand in smart phone text entry using one hand. Is the performance of subjects who use left-preferred hand in smart phone text entry worse than that of others who use right preferred hand among the right handed. This study tried to address these two questions. Thirty young male undergraduate students typed a text using a smart phone which has a touch-based QWERTY keyboard two times with both hands, right and left hand, respectively. The completion time, errors were measured in the text entry tasks. All of participants were right handed, but half of them preferred right hand if they have to use one hand in smart phone text entry and other half preferred left hand. The percentage that preferred hand has better performance than non-preferred hand in smart phone text entry using one hand is less than 90% for right-preferred hand and less than 70% for left-preferred hand. The performance of left hand preferred students is not worse than that of the right hand preferred in one hand text entry of smart phone.

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.355-372
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• 2017

Objective: The aim of this study is to investigate the performance and usability of ten-finger text entry on Tablet PCs. Background: Generally a soft keyboard is used on Tablet PCs. However, the soft keyboard's performance is usually worse than physical keyboard's performance. In this study, we proposed a modified keyboard for tablet PCs to improve the performance of ten-finger text entry and evaluated the performance and subjective ratings of the keyboard. Method: The modified soft keyboard that is suggested in this study was compared with current Google and Samsung soft keyboards on Tablet PCs. Results: The three keyboards were not significantly different in terms of typing speed, error rate, and mental workload and showed bad performance. Also, the subjective ratings were not shown positively. Conclusion: Based on our results, ten-finger text entry using soft keyboards on Tablet PCs seems to be very difficult. However, we need to research the possibility continuously since ten-finger text entry can improve typing speed. Application: Our study can be a starting point of research that explores ten-finger text entry on Tablet PCs. The new soft keyboard design can be one of the soft keyboard alternatives. However, the key factors to improve the performance and usability of the soft keyboard will not be 'key size' or 'convenience to typing special characters or numbers', but other factors (e.g., 'tactile feedback').

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.117-124
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• 2007

A few people are frequently using Korean text entry function in the mobile phone. To make matters worse, too many kinds of Korean text entry methods exist in the market, compelling mobile phone users to learn how to input texts all over again, whenever they purchase a new mobile phone. The purpose of this study is to propose a universal design of Korean text entry method for mobile phones. Several experiments and several questionnaire surveys were conducted in order to induce design factors for the universal design. Participants were mobile phone users with the diverse levels of text entry expertise and with the diverse ages. The results of this investigation were identical, irrespective of participants' age and expertise. The efficiency of the text entry method was not more important factor than memorability. The layout of vowels to keypad was preferred to map just 3 strokes to the 3 buttons so that users can make for themselves vowels that they want to input. The preference on the consonants layout was different according to investigation methods. According to the survey, it was preferred that consonants were arranged by alphabet order. However, the result of text entry speed measurement was that the arrangement by alphabet order was not superior to the typical arrangement. Such results may be used to design mobile phones for diverse users.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.1
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• pp.23-35
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• 2015

PURPOSE: People with physical disabilities such as cerebral palsy usually experience obstacles when interacting with computer through conventional keyboard because of their motor disabilities. The purpose of this study is empirically compare of text entry(alphabet and word) speed and accuracy using the three different keyboard type on four students(male 2 and female 2) with cerebral palsy. METHODS: This research design used a replicated single-case experimental approach to compare the individual performance. An alternating treatments design was used to examine the effectiveness of standard QWERTY keyboard and alternative keyboard(mini and big keyboard) on computer access for students with cerebral palsy. To avoid changes in posture that influence a keyboard character entry training and evaluation was carried out using his sitting in a wheelchair. Compass software program used in this study as an assessment tool to measure speed and accuracy when performance of text entry(alphabet and word). This was repeated until the stable status of reaction time. RESULTS: As a result, the alternative keyboard seems to be the most effective device for students with cerebral palsy to perform text entry. But various factors such as peculiarity of motor disabilities, experience and preferences of the user are heavily related. CONCLUSION: Thus, we must perform the objective and systematic assessment for computer access and if sustained training is accomplished, it could to improve speed and accuracy of text entry(alphabet and word).

• Journal of Practical Engineering Education
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• v.16 no.4
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• pp.459-469
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• 2024

Optimizing text entry in extended reality (XR) is important. However, most studies have focused on inputting alphabetic characters, so there is still insufficient research on inputting Korean characters. As a follow-up to our previous research, this paper deals with the effects of keyboard layout and augmented position on Korean text entry in the XR environment. For this purpose, we developed a virtual keyboard environment using the representative Korean keyboard layout "Du-Beol-Sik" across three augmented positions: mid-air, physical planar surface, and palmar surface. After conducting an experiment, we analyzed the effects of keyboard layout and augmented position on text entry by comparing the results of our previous research (the effect of augmented position on text entry based on the international standard Korean keyboard layout 'Chon-Ji-In'). The analysis results confirmed that the virtual keyboard performed the best overall when augmented in mid-air regardless of the keyboard layout. It was also confirmed that the keyboard layout had little effect on text entry. Based on detailed analyses, we suggest directions for providing a virtual keyboard for Korean text entries in the future.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.262-268
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• 2008

Recently, as the demand for multimedia services based on the wireless technologies and mobile devices increases, Full-touch screen mobile devices adopting touch screen keyboards are emerging to cope with the limited display size and take advantage of the flexibility in the design of user interfaces. However, the text entry task, which is one of the main features of the mobile devices, decreases the competitive advantages of the touch screen keyboards over the physical keyboards or keypads due to the lack of physical feedbacks and the frequent occurrence of mistyping. This study aims to introduce a novel text entry method named Fuzzy Touch and compare this method with the conventional text entry method on a touch screen keyboard in terms of the performance (time, number of touch) and the subjective ratings (ease of use, overall preference).

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.291-298
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• 2012

Objective: The aim of this study is to predict Korean text entry on touchscreens using ACT-R cognitive architecture. Background: Touchscreen application in devices such as satellite navigation devices, PDAs, mobile phones, etc. has been increasing, and the market size is expanding. Accordingly, there is an increasing interest to develop and evaluate the interface to enhance the user experience and increase satisfaction in the touchscreen environment. Method: In this study, Korean text entry performance in the touchscreen environment was analyzed using ACT-R. The ACT-R model considering the characteristics of the Korean language which is composed of vowels and consonants was established. Further, this study analyzed if the prediction of Korean text entry is possible through the ACT-R cognitive model. Results: In the analysis results, no significant difference on performance time between model prediction and empirical data was found. Conclusion: The proposed model can predict the accurate physical movement time as well as cognitive processing time. Application: This study is useful in conducting model-based evaluation on the text entry interface of the touchscreen and enabled quantitative and effective evaluation on the diverse types of Korean text input interfaces through the cognitive models.

• Proceedings of the Korea Society of Design Studies Conference
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• 2003.05a
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• pp.248-249
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• 2003

• IE interfaces
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• v.22 no.4
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• pp.329-335
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• 2009

Recently, the use of soft-keyboard is widespread and increases, because various handheld devices were developed such as PDA, navigation, mobile phones with enhanced competence of touchscreen. The use of soft-keyboard requires different characteristics compared to traditional hard-keyboard like QWERTY keyboard: no standard character layout, one finger entry, and cognitive processing time. In this study, therefore, the optimal soft-keyboard layout for one finger text entry in touchscreen environment was investigated among 6 keyboard layouts which were developed based on traditional characteristic of Korean text and the usage frequency of both vowels and consonants. As a result, the interface with Korean text invention order like 'ㄱㄴㄷㄹ' or 'ㅏㅑㅓㅕㅕ' was found to be better than the interface with usage frequency-based arrangement. Especially the vowels were most efficient when separated into two parts; located at the right-hand side and at right below the consonants. In conclusion, the keyboard layout with regard to the Korean text characteristic and the invention order was a more effective layout resulted from the minimum cognitive processing time.