In the Week One material you may or may not have run the test at http://html5test.com/ to see how well your browser supports HTML5. But you should also find out if that HTML5 is easily usable by people who rely on assistive technology without having to use special work arounds. The site http://html5accessibility.com/ tests which HTML5 features are accessibly supported by major browsers. This includes if they are keyboard accessible and if any accessibility related features are supported.