Touch screen technology has progressed a lot in the past few years and introduced a wave of various new touch screen based devices. Most of the touch screens are still not accessible to blind users, who have to take on various other ways to use them and to make them accessible.
Touch screens are inaccessible to the people with visual impairment because the human computer interface technique involves the user to visually locate objects on the screen and they do not provide verbal output to communicate where controls are located on the screen or what control the user has selected.
The purpose of this report is to evaluate the accessibility of the HTC Hero mobile phone for visually impaired people, in particular people that have totally lost their vision (referred as blind people) and people with partially lost vision (referred as partially sighted people or partially blind).
‘The World Health Organization (WHO) defines blindness as severe sight loss, where a person is unable to see clearly how many fingers are being held up at a distance of 3m (9.8 feet) or less, even when they are wearing glasses or contact lenses. However, someone who is blind may still have some degree of vision’.
Also the‘ WHO defines partial sightedness as where a person cannot clearly see how many fingers are being held up at a distance of 6m (19 feet) or less, even when they are wearing glasses or contact lenses’.
The HTC Hero has touch screen technology as the main means to input and output information. Additional issues for accessibility have been brought in as touch screen technology is being introduced to interfaces.
In this report I will investigate the issues that visually impaired people are facing when using human computer interfaces, especially with the touch screen phone HTC Hero.
1.1 Physical factors associated with visually impaired people and impact on the use of technology
People with total or partial blindness have decreased ability to perform the activities of daily living. Total and partial blindness affect a person’s ability to read, to determine the colour of items, and general day to day activities. These people must rely on memory or depend on someone else for help.
Visually impaired people rely on the technology to make their daily living easier. As visually impaired people can’t see where they walk, they run the risk of falling down much more than sighted people, therefore having mobile phone can be potentially life saver.
Also, visually impaired people are less likely to be doing activities like normal sighted people, so having a mobile phone is like their eyes to the world i.e. they can reach out to people at any time and feel less isolated.
The technology can help visually impaired people interact with others and communicate more effectively. Also the technology can enable visual impaired people to have more access to information, become more independent and achieve their individual aims and goals in life.
The market is flooded with a variety of mobile phones, but not all of them are easily usable by people with visual impairments. It is important that technology should assist visually impaired people of all ages.
Making the most of technology can have a very positive impact, helping people who are blind and partially sighted to increase their independence and more importantly feel and be as equal as normal sighted people.
1.2 What is accessibility?
According to Gnome, ‘Accessibility means helping people with disabilities to participate in substantial life activities. That includes work and the use of services, products, and information’.
From the definition, the understanding is that accessibility is the level to which something is accessible or usable by people with disabilities. For information technology, accessibility will mean people with disabilities be able to use software, hardware and other services that are designed and available for sighted people.
Software, hardware and other services should be universally designed.
Article 2 from The UN Convention on the Rights of Persons with Disabilities, says that: Universal design” means the design of products, environments, programmes and services to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design. “Universal design” shall not exclude assistive devices for particular groups of persons with disabilities where this is needed.
1.3 Considerations of human physical factors when developing a mobile phone for a visually impaired person
If we compare the mobile phones from a decade ago to todays phones, we notice that mobile phones are getting more and more complicated. In the past, all input was done via a keypad which could have been used by visually impaired people, because keypads had raised dot or raised bar on the 5 key which made it easy for visually impaired person to navigate and dial a number. Nowadays, with most mobile phones we use a touch screen or buttons and interact at any time; we can browse the internet, check our emails, take pictures and chat with friends.
A visually impaired person will not be able to see the screen of the mobile phone, or navigate through the touch phone’s screen. It appears that as we are getting more advanced in the technology of mobile phones the accessibility has not improved at the same rate as the advancement in the technology.
A visually impaired person cannot read the screen, cannot input information or read the output on a touch screen, and there isn’t an audible device to inform where they are navigating or have touched the phone. Therefore it is very important when developing mobile phones to take into account that visually impaired people can hear, can feel different surfaces with their fingers, but cannot read and navigate via a touch screen.
2. Review of HTC Hero
The HTC Hero is a small, all-in-one device that is used for communication and computing functions. It enables us to choose the applications we want to install and use, as well as personalize the range of applications to suit our needs.
Picture 1: Main Screen of HTC Hero mobile phone. Source: www.htc.com/www/product/hero/overview.html (Accessed 12 Feb 2011)
We can note from the main screen of the HTC Hero mobile phone (See Picture 1) that the standard keypad has been omitted and touch screen technology is used, the human computer interaction is done by touching the screen for input and output.
For a person to be able to make even a phone call on HTC Hero they need to see where on the screen they are touching; in other terms, the user of the phone interacts directly by seeing what they are touching.
2.1 Usability testing (the Heuristic evaluation)
The international standard ISO 9241 Part 11 (www.iso.org) defines usability as;
“The extent to which a product or system can be used by users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use”
Based on this definition for usability, the further understanding is that is a system or product is not accessible, consequentially is not usable to the set of users that are unable to access it.
Below is a brief heuristic evaluation of the HTC Hero mobile phone, to determine if it is accessible to a visually impaired person. The heuristic evaluation is broken into three sections:
Hardware is the physical mobile phone
Picture 2: HTC Hero. Source: http://www.engadget.com/2009/07/23/htc-hero-review/ (Accessed 12 Feb 2011)
The HTC Hero is very slim, light in weight, and can be held in the palm. The phone has definite shape and definite front/back/top/bottom to inform us which way round it should be used.
The visual information displayed on the main screen is in immediate contrast with the background and is clear, but visually impaired person will not be able to see it.
The phone has a white track ball (see arrow on Pic. 2) and touchpad. The track ball enables movement between screens and selects some services. A visually impaired person will not be able to see on which application or screen the trackball has stopped.
The HTC Hero has 6 buttons located on the bottom of the phone, their colour is in contrast with the immediate background, and a visually impaired person – by touching – will recognize that there are buttons.
The buttons are easy to press and have a positive “click” feel when pressed (although no noise is heard), which means that a visually impaired person will know they have pressed a button but not know the output function of the button pressed as there is no Braille labeling of buttons.
A visually impaired person will not be able to see that the HTC Hero is compatible with other devices such as USB cable and Wi-Fi and there are no instructions in alternative media (such as Braille or audio).
The HTC Hero supports input and output via the touchpad.
The input and output methods are via touchpad and they restrain the blind or partially sighted user from accessing the mobile phone.
The software does not play an audible sound when an action is committed such as pressing a button, and the visually impaired person will not know on what is the function of the button pressed.
The software does have speakerphone functionality, however the visually impaired person will not know how to access and navigate it. The HTC Hero does not have tactile input or output, such as Braille, to assist visually impaired users.
Services represent applications that can be accessed by touching an icon on the screen (See picture 3).
Picture 3: HTC Hero applications and services. Source: http://www.engadget.com/2009/07/23/htc-hero-review/ (Accessed 12 Feb 2011)
If the user wants to make a phone call they need to touch an icon on the screen (see arrow on Picture 3) and HTC hero will display list of all contacts. (See Picture 5).
Picture 4: HTC Hero – List of Contacts and numerical keyboard. Source: www.htc.com/www/product/hero/overview.html (Accessed 12 Feb 2011)
From pictures 3 and 4, it is noticeable that the input commands are on a touch screen, and the visually impaired person will not be able to use these functions on the smartphone HTC Hero.
The HTC Hero doesn’t have audio, Braille controls or magnifier to navigate to assist the visually impaired person to select an application or service such as the web services. Also, the web services have not been designed following the W3C guidelines for Mobile Web Best Practices.
2.2 Nielsen’s Ten Usability Heuristics
(Taken from Nielsen’s website www.useit.com )
Visibility of system status
Match between system and the real world
User control and freedom
Consistency and standards
Recognition rather than recall
Flexibility and efficiency of use
Aesthetic and minimalist design
Help users recognize, diagnose, and recover from errors
Help and documentation
3. Personal suggested improvements
The HTC Hero has excluded tactile information and there is a lack of facilities to enable visually impaired people to access the information displayed on the touch screen. There is also a lack of audible input and output which makes it inaccessible to visually impaired people.
Below are several personal suggestions that could improve the accessibility and usability of the HTC Hero for visually impaired people:
3.1 Audio Input and Output
Introducing a form of Audio Input and Output functionality to the software will make an enormous difference to the HTC Hero. One suggestion would be a system where the user can press an icon on the touchpad and the phone audibly informs the user which icon the have pressed and navigates them to the next logical steps.
3.2 Tactile Input and Output
Adding tactile input and output functionality to the HTC Hero could potentially help visually impaired people. The system should have the option to switch Braille on and off. Although Braille literacy is very low in number (only 2% of UK blind people can read Braille) this functionality within the software should not be omitted.
3.3 Touch screen advances
A major improvement on touch screen accessibility would be made by adopting the audio-haptic interface techniques to allow non-visual access to touch screen appliances, as suggested per Vanderheiden’s Talking Fingertip Technique (Vanderheiden 2010). The Talking Fingertip Technique is a touch screen that speaks the descriptive names of the controls as the user accesses the screen by touch.
3.4 Introduce Mobile Magnifier
Adding an assisted device such as a Mobile Magnifier would help partially sighted people on touch screen phone of the HTC Hero. The mobile magnifier enlarges and enhances the readability of the screen.
3.5 Follow W3C Guidelines for Mobile Web Services
The HTC Hero could adopt the W3C Guidelines for developing Mobile Web Services to improve the accessibility for visually impaired people.
In this report I have investigated the issues of accessibility faced by visually impaired people when using human computer interface, in particular the touch screen mobile phone. I have used the example of the HTC Hero mobile phone for a case study of accessibility and usability. I have evaluated it against the current accessibility and usability guidelines.
During my research, I have found several issues that should be addressed if the HTC Hero is to become accessible and usable by visually impaired people. These issues include a lack of usage of assisted devices such as:
audio input and output
tactile input and output
magnifier for visually impaired people
not following the W3C Guidelines for Mobile Web Services
I have suggested several improvements to the HTC Hero that can be made by using existing technology. These suggestions for improvements include following W3C guidelines for improving accessibility for mobile phones, introducing audio input and output, tactile input and output, adoption the Vanderheiden’s Talking Fingertip Technique and possibly the adoption of mobile magnifier.
Hopefully, these suggestions will help developers to add accessibility to their applications in a way that is straight forward for the developer and intuitive for the user.
Definition for blindness and partial blind: http://www.nhs.uk/conditions/Visual-impairment/Pages/Introduction.aspx (Last Accessed 12 Feb 2011).
Definition of Accessibility, Gnome: http://library.gnome.org/devel/accessibility-devel-guide/stable/gad.html.en (Last Accessed 12 Feb 2011).
Definition of usability: http://www.iso.org/iso/ (Last Accessed 12 Feb 2011).
Mobile Magnifier, http://www.sightandsound.co.uk/products/?category=1&subcat=31&minorcat=8 (Last Accessed 27 Feb 2011).
Pictures1, 2 3: www.htc.com/www/product/hero/overview.html (Last Accessed 12 Feb 2011).
Picture 4: http://www.engadget.com/2009/07/23/htc-hero-review/ (Last Accessed 12 Feb 2011).
Statistics about Braille literacy: http://www.webbie.org.uk/webbie.htm (Last Accessed 26 Feb 2011).
UN convention for the rights of people with disabilities: http://www.un.org/disabilities/convention/conventionfull.shtml (Last Accessed 26 Feb 2011).
Use of audio-haptic interface (Vanderheiden) http://trace.wisc.edu/docs/touchscreen/chi_conf.htm (Last Accessed 27 Feb 2011).
W3C guidelines for Mobile http://www.w3.org/TR/mobile-bp/ (Last Accessed 27 Feb 2011).