Checklist for Touchscreens

No significant benefits Minor benefits Major benefits
No significant benefits Minor benefits Major benefits

Menu systems should be helpful and logical
General layout of the phone, functions and interaction principles should be standardised for all devices

Screens
Good contrast with the background should be provided for text and graphics
There is provision for adequate, adjustable illumination of the LCD display whenever possible
Use back illumination of LCD screens whenever possible (a simple regulation of contrast or brightness is not sufficient)
Anti-glare provision to avoid reflections whenever possible
It is possible to tilt the display
Combinations of blue, green and violet should be avoided
Colour alone should not carry information
A line by line presentation is often preferable to a single line of scrolling text

Touchscreens
The touch screen is shielded from sunlight
The screen is angled towards the horizontal to provide arm/wrist support
The screen is perpendicular to the line of sight
The text and background colour combination is of high contrast
Use of blue, green and violet is kept to a minimum
There is no noticeable flicker on the screen
The structure of the visual display allows the user to predict where to find information and how to use it

Fonts
Kerning between specific characters is sufficient so as to ensure legibility
A minimum type size of 12 point is used
There is clear letter spacing between each character
The use of italic fonts is avoided as they are more difficult and slower to read
Avoid patterned backgrounds for fonts
Ensure the font has both upper and lower case letters as it is easier to read text in mixed case
There is a system for enlarging text on the screen
Information should be presented in small amounts which can be easily retained

Keys
There is good visual contrast between the keys and body of the phone
Key tops are convex, or flat with a raised edge
Keys are as large a size as possible
Keys are internally illuminated
Visual markings on the keys are clear and as large as possible
Keys are raised 5mm above the body of the phone
There is auditory feedback of key activation
There is tactile feedback of key activation
The "5" key and the "F" and "J" keys on a QWERTY keyboard are marked tactually
There is a voice mode selction that announces all key presses

Audio output
There is an option to switch off verbal feedback when/if not required
There is an option to switch off non-speech sounds, if used
Voice warnings should be presented in a voice that is different from other voices that will be heard in the task situation
Maximise the intelligibility of the messages
Make the voice as natural as possible so people are more likely to accept it
If the message is missed, it is beneficial for people to be able to replay it
If the message is familiar, the ability to interrupt the message would be beneficial for experienced users
Where the choice of messages is relatively limited, human voices are preferred because synthetic speech is less intelligible and less preferred
Use non-speech audio messages only for the purposes of alerting

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