There are a number of factors that can influence an assessment. It is so important to ensure that conditions are favourable before deciding whether or not one of our products is suitable for a client. Positioning is one of the most important factors to take into consideration, particularly when doing an eye tracking assessment. Positioning refers to how the person is seated and where the device is placed in relation to the user.
The first time I tried to assess S, she got an excellent calibration which meant that the eye tracker was picking up her eyes and tracking them almost perfectly. The communication software that we used, Grid 3, has interesting and exciting graphics that move across the screen to hold the user’s attention as the eye tracker tries to calibrate to the user’s eyes. S particularly enjoyed the animated bird. However, she was not able to accurately select anything on the screen. A successful calibration does not always guarantee that eye tracking is the right option for a client and at this point I wasn't sure that eye tracking was a viable option for S - perhaps there were other aspects of her vision that needed to be worked on first. At the first assessment, S did not have her chair with her and did not seem to be positioned properly. I decided to try one more assessment to be sure.
For the second assessment, her mom brought the correct chair and her physio ensured that S was properly positioned. We once more obtained an excellent calibration. Because she enjoyed the bird calibration target so much, I started with the ‘Fruit Splat’ game in Look 2 Learn. Look 2 Learn is a software title that consists of a number of fun games for users learning to use the eye tracker. She quickly realised that she could control what happened on the screen and followed directions like 'Get the banana,' and 'Look at the big daddy cloud - what sound does he make?' She found the Look 2 Learn games and the games on Grid 3 really motivating.
We moved onto a simple 'more' and 'stop' grid for bubbles and getting kisses from her dolly. For these activities she tended to go back to her usual gestures for yes and no, rather than use the software interface. I used this opportunity to explain how we can model to show her how she can use her eyes to tell us what she needs, while still responding to every communication attempt she made.
Grid 3 allows for easy editing of grids and even allows you to create your own grids. I had premade a communication grid in Grid 3 to represent some of her favourite games/toys that included 'baking' with toy food and 'smoothie' with toy fruit, bugs and a switch adapted toy blender.
She selected the symbol of the biscuit for ‘baking’ but when asked if we must bring out the toy food, she shook her head for no. It was confusing until we realised she had seen a container of baked goods her mom had brought, and was asking for that! She selected ‘smoothie’ and then shook her head when we asked her if she wanted to bring out the toy blender. The physio was drinking coffee and the little girl was asking for it, using the closest symbol that she had available!
Using a combination of the communication grid, controlled with her eyes, and her yes & no gestures, she had successfully communicated what she wanted!
If we had only conducted one assessment, we might have decided that eye tracking was not for S and tried to come up with another way for her to use a computer to communicate. However, just by ensuring that she was positioned properly, her accuracy was sufficiently improved, and we were able to determine that she is an excellent candidate for eye tracking.
