[car] @emplums I agree with @garcialo to have them use their sites. You might start with simply getting them to navigate and activate things with the keyboard only. This can be quite surprising if they haven't thought about accessibility before. Get them to tab a few times, and if you don't see the focus outline, ask "where is focus right now?" (i.e. maybe they turned off outlines and didn't provide focus styles; or maybe they have offscreen elements or scaled-to-size-0 elements that shouldn't have tabindex=0 until they become visible). Get them to activate buttons and other input things with space/enter. If there are lists, trees, combos, etc that have click behavior, then they need to also handle arrow keys and selection/activation with space/enter. If they have any complex controls, get them to show you how these work with the keyboard. Open dialogs/side panels, etc with the keyboard and make sure Esc closes them. If there are any modal dialog things (i.e. pop-up elements that need an answer before the user can continue) then make sure they can't just tab out of them. Talk about keyboard traps.