WCAG Levels: Impact Against Effort

The Web Content Accessibility Guidelines (WCAG) sort their success criteria into three levels: A, AA and AAA. People often read them as grades. I find two pyramids more useful.

• User impact is a pyramid with A at its wide base. Level A covers the things that block people outright: no label, no keyboard access, no text alternative. Fixing those first removes the most barriers.
• Testing effort per issue is the same pyramid upside down. A single AAA issue takes the most work to find, judge and fix.

Put together: start with the barriers that stop people outright. Get every screen to solid A, then AA, and keep going to AAA. One screen polished to AAA while the rest still block people at A leaves most of the app closed.