Overview
In keeping with our overall accessibility statement, the micro:bit CreateAI web application has been designed with web accessibility in mind. We strive to meet and exceed Web Content Accessibility Guidelines version (WCAG) 2.1 AA. On this page we detail known deviation and specific advice.
Keyboard access
micro:bit CreateAI is accessible with a keyboard with one exception - when you review data features for a data sample, you cannot access the descriptions of what each feature means.
Adding the very large number of tab stops to access the data features tooltips would harm overall page navigation. We are considering alternative ways to provide this information. The list of tooltips is given below in order. Each is repeated for x, y, and z in that order.
- Maximum point among all x-direction data points
- Mean value for x-direction data
- Minimum point among all x-direction data points
- Average deviation from 0 among all x-direction data points
- Number of extremes among all x-direction data points
- Sum of x-direction data
- Rate at which acceleration transitions between positive and negative for x-direction data points
- Root mean square value for all x-direction data points
You can also use the B button on the micro:bit to quickly record a new data sample for the currently-selected action.
Screen reader access
micro:bit CreateAI is accessible to screen readers, with the following exceptions:
- The visual appearance of time-series graphs for each sample is not screen-reader accessible.
- The live prediction and graphs are partially screen-reader accessible. Before you have trained the model, the data graph just shows a live x, y, z trace, which is not accessible to a screen reader. After training, a live-region notifies you of the currently predicted action, and you can access the current confidence value for each action individually.
- Data features for each sample are a visual representation that isn’t currently accessible with a screen reader.
- When pairing a micro:bit over Bluetooth, you will be asked to fill in the number of LEDs visible on the micro:bit. So long as you do not skip the prior “Connect USB cable to micro:bit” step, the form will be pre-populated with the correct code and you will not need to change any numbers. If you do skip the prior step (this can save time if the data collection program is already on the micro:bit) then you may need sighted assistance to see which LEDs are lit on the micro:bit. If you always use the same micro:bit with CreateAI, then the pattern will be remembered even if you skip.
- When you record a new data sample, there is a 3 second countdown followed by one second of data capture which is communicated with a progress bar. The countdown may not be communicated well by all screen readers. The recording process can be cancelled by pressing Esc. In NVDA you may find it helpful to skip reading the recoding dialog contents (press the Control key) so that NVDA promptly reads the recording countdown.
The main CreateAI web pages have multiple regions defined to help you navigate quickly around the page. The “main” landmark contains all the samples and data relating to each action you are teaching the AI. The “data samples toolbar” contains the page specific buttons for training or testing a model. The “micro:bit data connection” region handles micro:bit connection and disconnection, as well as showing live data.
To quickly add samples for a particular action, you can press the B button (the right hand button on the front of the micro:bit, with the notches on the bottom and the USB port on the top) to record a sample. There is a 3 second countdown followed by one second of data recording.
We welcome feedback and suggestions for how to make the live data more accessible to screen reader users - please contact us on accessibility@microbit.org.
Adapting the appearance of the page
Colour blindness and contrast
In the settings menu you can change the colour scheme for the data (x, y, z) graphs to 2 colourblind-friendly alternative options. We plan to implement more styling options soon.
Responsive zoom
Currently the web page adapts well to up to 200% zoom, but becomes unusable between 200-400% zoom. We are working on improving this.
Planned improvements
We are aware of a few issues which we are actively working on fixing by December 2024:
- More styling options for the graph
We are also gathering feedback on improvements we can make to the accessibility of the live data components with a screen reader.