Covenant Journal of Informatics and Communication Technology (CJICT) Vol. 1, No. 2, December, 2013. Survey of Eye-Free Text Entry Techniques of Touch Screen Mobile Devices Designed for Visually Impaired Users Sonali Banubakode1, Chitra Dhawale 2 [email protected] 2MCA Department, P.R. Pote College, Amravati, India [email protected] Abstract: Now a days touch screen mobiles are becoming more popular amongst sighted as well visually impaired people due to its simple interface and efficient interaction techniques. Most of the touch screen devices designed for visually impaired users based on screen readers, haptic and different user interface (UI). In this paper we present a critical review of different keypad layouts designed for visually impaired users and their effect on text entry speed. And try to list out key issues to extend accessibility and text entry rate of touch screen devices. Keywords: Text entry rate, touch screen mobile devices, visually impaired users. I. Introduction increasingly common in both sighted Visual impairment describes any and visually impaired people. These kind of vision loss, whether it‟s devices used not only for about total blindness or partial vision entertainment and communication loss. Some people are totally blind purpose but for learning, browsing, but many others have legal e-billing and many more. But they blindness. They don‟t have enough are highly visual demanding. Touch vision to see the object stands 20 feet screen is highly sensitive; it contains away from them (Arditi & lots of tiny icons and requires more Rosenthal, 1998). According to concentration as well as fast action. recent statistics of WHO (Chatterjee, It is not easy for any person with 1198) 285 million people are vision problem to handle such visually impaired. From which 39 devices satisfying above demands. million are blind and 246 have low Though there are some touch screen vision. devices available for vision impaired Touch screen mobile devices known people, it remains inaccessible in as Smartphone, becoming many ways. Most of the available devices use screen readers like Jaws, 1 Covenant Journal of Informatics and Communication Technology (CJICT) Vol. 1, No. 2, December, 2013. Apple Voice Over, etc; screen degree as to qualify as an additional magnifiers and support tactile support need through a significant feedback. These techniques help to limitation of visual capability support navigate the screens and resulting from either disease, trauma, search the desire words or icons. or congenital or degenerative Some devices come with different conditions that cannot be corrected types of keypad layouts other than by conventional means, such as traditional one. They also support refractive correction or medication TTS techniques and tactile feedbacks (WHO; Bill Text,2003-2004; Belote which help to enter text without & Lary,2006). watching the screen. Though these Problems faced by vision impaired ;n techniques try to make touch screen size which causes inconvenience in devices more users friendly for handling the device and some have visually impaired people, there are too small to select only one letter at a some of drawbacks like: lack of time. clearness in sound, more time Button size: Some devices have consumption in navigation, etc; fails too small buttons that either do not to increase accessibility of these click when pressed or adjacent other devices. Also the text entry rate is button is clicked. Thus provide not so good which reduces fast wrong feedback. responses on touch screen. Keypad layouts: Every device In next section, we discuss about provides different layouts of accessibility problems of keypads. Novice users have to spend touchscreen devices faced by more time on learning and being visually impaired people. In section familiar to it. III, related work in this area is Menus: Large number of menus studied. In section IV, we discuss causes difficulties in understanding about various text entry evaluation and selecting. metrics. In section V, comparative Text size: Small text size is unable analysis of available devices based to read. on keypad layout is performed. Feedback: Some sound and tactile Section VI concluded our survey feedbacks are not clear to easily with providing some key issues to understand. improve text entry technique and Text entry rate: Low text entry accessibility of touch screen mobile rate causes obstacles in fast typing devices for vision loss users. and response. Time Delay: Some approaches II. Visual Impairment and have more time laps between key Accessibility Problems touch and recognition which causes Visual impairment ( or vision irritation and unwanted time loss of impairment ) is vision loss to such a expert users. 2 Covenant Journal of Informatics and Communication Technology (CJICT) Vol. 1, No. 2, December, 2013. Cost: Disabled users either have to is displayed on screen, rather than purchase mobile devices developed using mouse or touchpad; secondly, for them or have to download that does not require any various application required making intermediate device that would need the device accessible by paying large to be held in hand (other than stylus). amount. Every user can not afford it. 1). Single-touch based strategies: Basic touch screen functionality is I. Touchscreen Mobile Devices for single-touch, where you touch the the Visual Impaired Users screen like mouse moving around the From last two decades frequency of screen and „tap‟ the screen like a evaluating new text entry method mouse click. In this strategy a finger increases due to recent and or any pointing device (gesture) is heightened interest in touchscreen ( used to enter the text i.e. Smartphone) and use of SMS. According to statistics 9.8T SMS 2). Multi touch-based strategies: messages were sent in 2012 Multi-touch refers to ability of touch (Factbrowser.com, 2012). In 1997 sensing surface to recognize the first touchscreen was developed by presence of two or more points of Dr. Sam Hurst of Elographics, now contacts on the surface. This dual- known as Elo TechSystems (Brown point awareness is used for pinch to et.al, 1971). The design called, zoom or activating predefined “elograph”, was a computer input programs. devices that uses resistive A. Text Entry factors touchscreen technology. Generally Following are some factors on touchscreen has two main attributes: which affects text entry. first, one directly interacts with what TABLE I: TEXT ENTRY FACTORS Text Entry Explanation Factors Speed/Efficiency Speed of text to be keyed by either using muiltitap or single touch Learnability Comfortness of user to learn the text entry mechanism. Simplicity simplicity to use text entry mechanism Navigation Comfortness for key selection while texting (eg. Punctuation, blank space, capitalization, etc) 3 Covenant Journal of Informatics and Communication Technology (CJICT) Vol. 1, No. 2, December, 2013. It is seen that all these factors are searching for a specific character or related with keypad design and group of characters along the screen. hence text entry is strongly affected Also this approach suffers from by layout of keypad of mobile problem of segmentation, when the device. character is on the same key as previous one. B. Keypad Layout One of the important factors In 2011 Aakar Gupta and Navkar responsible for text entry speed is Samdaria implemented SVIFT keypad layout. Researchers proposed (Gupta & Samdaria,2011) which different keypad layouts for their uses vibrotactile technique for eye- applications. free text entry. The technique involves expanding the text-entry 1) Telephone keypad mode to a full screen format and This multi-touch approach is used by innovating over the old-style T9 and Sanchez and Aguayo in 2007. They telephone keypad design. It makes proposed 9-button virtual keyboard use of multiple input and feedback layout called as Mobile Messenger interactions – swipe, pause, circle, for the blind (Yfantidis & hand-waving, audio and vibrotactile. Evreinoy,2006). It is a messaging Its text entry speed is 4.75 wpm. But system for mobile devices having its input mechanism for special multiple characters on each key character is not efficient. Also supported by audio feedback. It has number appears in separate mode less number of targets which are which is not convenient to select. placed at easy- to-reference location 2) Stroke based Keypad e.g. near the edge of the screen that make blind user easily find them. In 1993 Goldberg and Richerdson But problem increases when first proposed Unistokes [13] based numbers of targets are increases. In keypad. They use Single-touch such target-based system text strategy for text entry. These strokes entering become more difficult. are very simple and user writes it without watching the stylus. Its text In 2008 Guerreiro et al. (Guerreiro entry rate was 16 wpm. But these et al ,2008) presents 12 button based strokes are different from regular approach of touch screen mobile handwritten or printed letters. Hence known as MultiTap. Each button they must be learned and an expert is features a set of characters. It proved needed for fast text entry. Also to be faster as it offers a more direct Unistrokes could not used for mapping between input and desired number, punctuation, or symbolic output. Its text entry rate was 0.88 characters. wpm with 15.28% error rate. But with MultiTap problem arises during 4 Covenant Journal of Informatics and Communication Technology (CJICT) Vol. 1, No. 2, December, 2013. In 1995 Palm Inc. also designed of list use L-select gesture. Its single-stroke alphabets recognition interface is entirely speech-based and system that uses Graffiti strokes it does not support any visual (Blickenstorfer,1995). It was used to feedback. Its text entry rate is 27 draw upper-case characters blindly with 14.1% error rate. The major with stylus on touch panel. It is problem with Slide Rule is that it has similar with hand written or printed no visual representation.