If they are physically and cognitively capable then two switches can give your pupil a lot more control. With two switches they have the flexibility of skipping past cells they do not want in order to make their select faster. It also allows them to relax a lot more as they do not need to constantly concentrate on the scanning box as this is now under their full control.
Two switch scanning can be more physically demanding than single-switch scanning, but it does away with the tricky issues of timing and anticipation. Your pupil needs to demonstrate that they can make the correct choice between the two switches.
When using the single switch scanning method the user has to remain very focused on the scanning and avoid getting distracted by other goings-on in the classroom.
Note: If you can't see an animation on the left then your browser has blocked this content as it feels it might be malicious. If this is the case then I can assure that my content is harmless and you can enable it by clicking on the warning banner above.
In order to use two-switch scanning you need to procure two suitable switches and a switch interface for getting these into the computer.
Once you've got your switches connected to your computer you'll also need to tell Clicker that they're there. Here's how to accomplish this:
Make sure Clicker is running and that you are logged on as the person you want these settings to affect.
Now got to the Options menu and click on User Access.
This should bring up the Access dialog box. Under Access Method, select Two Switches.
In case you're getting a mysterious sense of deja-vue, the following steps are exactly the same as for single switches.
Now you will have to tell Clicker where the switch is plugged in. Go to the Switch Connection tab and choose from the list whichever is relevant to you.
If you're using the Crick USB Switch Interface box then select this option from the list.
If you are using a serial port adapter for your switches then you'll need to select one of the COM ports. If you're unsure then start at COM 1, click OK, and try your switch. If you can't select a cell try plugging your switch into another jack port. If things still don't go anywhere then go back to Options, User Access, Switch Connection and try COM 2.
If you're using switches that plug into your keyboard then select the Up & Left Arrow Keys option. If you can't set your switches to these keys then you'll have to load the third-party switch driver that was supplied with your switch-enabled keyboard or other interface.
Once you've got Clicker scanning and your switch selecting, you'll need to adjust the timings so that it's not to slow or fast for your user. Go to Options and User Access again. This time click the Timings tab.
The first setting is the Scan Delay. This specifies the amount of time that the grid will wait at a cell before it moves on to the next one. Too slow a setting and it could take ages to scan a grid. Too fast and your user might not be able to respond in time and hit the switch before it's moved on to the next cell.
A setting of 20 is around one second on my computer, but it could vary.
If your user tends to tap the switch at the wrong times, then you could try putting up the Acceptance Delay. This will mean that your user will have to hold the switch down for a certain amount of time before clicker will accept and select the cell.
A setting of 20 forces the user to hold the switch down for around half a second.
The Debounce Delay is important as some switch users tend to tremble when they hit their switch. By raising the debounce value you'll be able to stop this from happening. Clicker will accept the first switch, but will then wait for the specified time before it will accept any more. Raising it too high could stop your user from being able to select proceeding cells, so watch out!
Return to the Clicker Access Methods Contents Page
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 2.5 License.
Privacy Policy. Contact Me. Charlie Danger MMVI.