To select a preferred interface, the user could simply press a button or select from a menu on the screen. This is unlikely to find favour with service providers if it significantly increased the time taken to undertake the transaction, but it may be viable for simple operations such as increasing audio amplification on a telephone. For applications such as a cash dispenser, the user's preferences could be stored on a central computer and implemented as soon as the PIN (personal identification number) has been entered. Storing personal data centrally may give rise to data protection concerns.

However, another method would be to store the information on the customer's card. With a magnetic stripe card there is very limited spare capacity for storing this information (but this method has been used for storing the user's preference for displayed language, eg. English or French). A smart card has fewer restrictions on storage capacity so appears to be ideal for this purpose.

The user could request a particular interface by:

• Filling in an application form

• At a help desk/registration station

• Choosing at a terminal

• Asking a health professional (eg. audiologist) to do it on their behalf

Many disabled users would like to be able to select and store their preferred interface whenever they use the card at a terminal. However practical and security constraints may restrict this choice to being made at the time of issuing the card.

It is essential that information is only stored on a card with the consent of the user.

Ideally the coding should allow for either specific user preferences or a general description of the impairment, and the coding should be in accordance to ASN.1 notation (ISO 8824 & 8825). It is important that any coding scheme can be extended as and when needed, and allow the card to be used in a number of very different terminals, eg. ticket machines, car parking meters, cash dispensers and public telephones. The following two pages show a possible structure for this coding.

User Preferences

Item	ASCII	Data size in octets	Meaning of data integer used
Preferences	P	indefinite	n.a.
Visual parametres	V	indefinite	n.a.
Symbols	y	1	1=text only, 2=text and symbols, 3=symbols only
Sign language	l	1	1-yes, 0=no
Text size	z	1	millimetre
Text colour	t	3	1st octet=red, 2nd octet=green, 3rd octet=blue
Background colour	b	3	1st octet=red, 2nd octet=green, 3rd octet=blue
Exclude colours	e	n*3	n multiples of 1st octet=red, 2nd octet=green, 3rd octet=blue
Avoid colour combinations	a	m*3*2	m multiples of pairs of 1st octet=red, 2nd octet=green, 3rd octet=blue
Position of screen	p	3	1st octet=x, 2nd octet=y, 3rd octet=z
Hearing parameters	H	indefinite	n.a.
Voice out	v	indefinite	n.a.
Voice device	v	1	1=loudspeaker, 2=headset, 3=both
Pitch	p	1	1=male voice, 2=female voice
Speech rate	s	1	words/minute
Sound amplification	s	1	most significant bit: 0=postitive value, 1=negative value; the 7 least significant bits denote the offset amount in dBA from the terminalšs normal sound level
High frequency amplification	I	1	as above
Low frequency amplification	l	1	as above
Hearing aid communication	h	1	1=magnetic inductive coupling
Touch parameters	T	indefinite	n.a.
Braille	b	0	Absent
Speech parameters	S	indefinite	n.a.
Voice input	v	0	Absent
Motion parameters	M	indefinite	n.a.
Keyboard	k	0	Absent
PIN pad	p	1	1=type 123, 2=type 789
Touch screen	s	indefinite	n.a.
Button size	b	1	1=normal, 2=medium, 3=large, 4=very large
Click type	c	1	1=click up, 2=click down
Sensitivity	s	1	1=low, 2=normal, 3=moderate, 4=high
Position of input device	I	3	XYZ coordinate
Time outs	t	1	time in decaseconds
Language parameters	L	indefinite	n.a.
Language	l	1	to ISO specification
Dialogue level	d	1	1=normal, 2=simple, 3=very simple
Text complexity	c	1	1=normal, 2=simple, 3=very simple
Text density	t	1	1=normal, 2=low, 3=very low

User Profile

The general description of the impairment would include visual impairment (eg. reduced acuity, reduced field of vision, colour blindness), hearing impairment (eg. loss of high frequencies), cognitive impairments (eg. reduced short term memory), dexterity problems (eg. reduced reach, tremor) and dyslexia.

Item	ASCII	Data size in octets	Meaning of data integer used
User profile	U	indefinite	n.a.
Hearing impairments	H	indefinite	n.a.
General	g	1	1=light, 2=medium, 3=severe, 4=totally deaf
Speech discrimination	s	1	1=light, 2=medium, 3=severe
Left ear	l	indefinite	n.a.
Right ear	r	indefinite	n.a.
Low frequency reduction	l	1	1=light, 2=medium, 3=severe
High frequency reduction	h	1	1=light, 2=medium, 3=severe
Visual impairments	V	indefinite	n.a.
Acuity reduction	a	1	1=light, 2=medium, 3=severe, 4=totally blind
Reduced field of vision	f	1	1=light, 2=medium, 3=severe
Colour blind	c	indefinite	n.a.
Red/Green	r	1	1=light, 2=medium, 3=severe
Blue/Yellow	v	1	1=light, 2=medium, 3=severe
Cognitive impairments	C	indefinite	n.a.
Reduced intellectual processing	I	1	1=light, 2=medium, 3=severe
Reduced concentration	c	1	1=light, 2=medium, 3=severe
Reduced language comprehension	a	1	1=light, 2=medium, 3=severe
Reduced short term memory	s	1	1=light, 2=medium, 3=severe
Reduced long term memory	l	1	1=light, 2=medium, 3=severe
Dexterity problems	B	indefinite	n.a.
Lack of upper limbs	u	1	1=left hand, 2=right hand, 3=both hands, 4=left arm, 5=right arm, 6=both arms
Reduced finger mobility	f	1	1=light, 2=medium, 3=severe
Reduced reach	r	1	1=light, 2=medium, 3=severe
Reduced coordination	c	1	1=light, 2=medium, 3=severe
Tremor	t	1	1=light, 2=medium, 3=severe
Dyslexia	D	indefinite	n.a.
Reduced reading	r	1	1=light, 2=medium, 3=severe
Reduced writing	w	1	1=light, 2=medium, 3=severe

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