Access Methods

What are the two access methods?

1. Direct Selection

2. Scanning

3 components of access

1. methods

2. strategies

3. techniques

Access definition

How the individual who relies on an AAC system interacts with or selects words/symbols/representations from their system.

Types of Direct Selection

• Physical Touch/Contact

• Physical Pressure (pressing/depressing)

• No contact

• Speech Recognition (spinal cord injury)

  • text, email, surf the web

• Brain Computer Interfaces (BCI)

  • electrodes attach to head to train computer

Physical Touch/Contact

(pointing to/touching the target)

• Physical contact with non-electronic or touchscreen systems

Physical Pressure/Depression

(keyboard, touchpad)

• body part

• body part extension (headstick used to point)

No contact

Pointing-without touching the surface

• eye gaze

• head tracking (reflective dot, iOS technology)

• laser pointer

other considerations for direct selection

• Timed activation/Dwell time

• Release Activation

• Filtered/Average Activation

release activation

say it when you touch it, or not until you let it go

for those who may have motor control issues

Timed activation/Dwell time reduces what?

inadvertent activations and motor control demands

If they look at a lot of icons, that doesn’t mean they are selecting all of them, need to add a wait time for a formal selection

why is scanning also considered indirect selection?

The AAC user is not directly interacting but instead they are using an external tool

scanning types

• Partner Assisted Scanning

• Switch Scanning

• Scan/Scroll Sequentially Patterns

• Scanning Modes

how are options presented for partner assisted scanning?

either visually or auditorily or both

they need the cognitive ability to accurately say yes/no (eye gaze or a head nod)

ABC

access before communication

you need to decide how they access first

Switch Scanning

• Size, shape, manner

• Manner: mechanical, electronic, EMG switches

Scan/Scroll Sequentially Patterns

• Circular

• Linear (columns)

• Group-Item (columns/rows-quadrants)

Scanning Modes

• Automatic- always going

• Inverse

• Step or 2-step- one button to scan icon, one button to select or the same one hold it down