Provide Proof of Progress

[mgifford]

If you are scanning pages with purple hats, demonstate that there is improvement over time.

Build a score based on axe criteria which addresses severity - Score = (critical3 + serious2 + moderate1.5 minor) / urls5 - which allows you to easily compare a 1000 page site to a 10000 page site with a numeric value which lets you determine if the site is getting better or worse for users. https://github.com/CivicActions/purple-hats/blob/master/mergeAxeResults.js#L383

This just makes it easier for people to see relative scores.

It is also critical to remind folks about Goodhart's law, that states: "When a measure becomes a target, it ceases to be a good measure". A score based on axe results is just one way to measure accessibility.