Page 132 - Handbook of Electronic Assistive Technology

120 HANDBOOK OF ELECTRONIC ASSISTIVE TECHNOLOGY

Table 5-2 Touchscreen Access Settings

Access Option What It Does Why It Is Useful
Hold Duration Hold Duration sets a time that the user Hold Duration ignores short accidental taps.
has to tap and hold before the touch is It is helpful for users who have difficulty
accepted. targeting accurately and who accidentally
tap the wrong item.
Visual feedback or Displays a circle or border around items on Provides visual feedback of the item that is
cue screen as they are tracked. currently being touched.
Hold or dwell visual Displays a ‘countdown’ timer of the time Provides visual feedback while the hold
feedback remaining for hold duration/dwell, as it times duration or dwell time times out until the
out to selection. item is selected.
Auditory feedback Provides an auditory click or feedback on Provides auditory feedback to confirm when
initial touch and/or selection. an item is first touched and then selected.
This can be particularly helpful when a Hold
Duration is specified.
Ignore Repeats Ignore Repeats will filter and ignore any Ignore Repeats is helpful for users who
repeated taps within a specified time. bounce or tremor when tapping the screen.
Select on First Touch Accepts the first location touched as the tap. This is helpful if you touch and then move
before the selection is accepted.
Select on Release Accepts the final location touched, when the This is helpful if you have difficulty targeting
user lifts up from the screen. with the initial touch, but can drag to the
required location and then lift off.

circular or shrinking visual timer, ‘Activate on first item or last item touched’ and ‘Prevent
repeat activations’ (Ignore Repeats).
The touch and response settings and behaviour of different devices and applications
does therefore vary and it is important to be aware of these possibilities when considering
access and assistive technologies.

Styli
Some users are unable or have difficulty touching the screen accurately but may be able to
access the device using a stylus or stick. Since most touchscreens are capacitive, the stylus
must provide electrical conductivity between the user’s skin and the touchscreen.
Alternative Access to Touchscreen Devices

There are many alternatives for users who cannot access a touchscreen directly.
Touchscreen devices based on MacOS, Windows, Android and Chromebook operating
systems can be accessed using a mouse or the full gamut of USB and Bluetooth pointing
devices, including eye gaze. However, standard mice and pointing devices cannot be con-
nected to an iOS device because they lack a USB port or pointing device capability; the
only alternatives to the touchscreen are hardware keyboards, speech recognition (Siri) or
scanning with switches.