Season 0. The designer agreement read is on Nov 6.
Rams puts one number on how well an interface is designed. This page is the method behind that number: what we look at, how it is computed, how sure we are, and where it can be wrong. It is our opinion, held to a fixed method and checked against designers.
One judge and one method, applied to three kinds of work.
Every model builds the same pages from the same written briefs. We render each page and grade it. Scored 0 to 100.
The public home pages of well-known products, rendered as a signed-out visitor sees them. The first cut scored 140 sites on the same scale as the models.
The UI code in a pull request, read against 348 public rules. Scored 0 to 100 and posted on the pull request with fixes.
Rendered pages for the two indexes. Code for the pull request score.
Plain arithmetic on the judge's grades and the review's findings.
(grade sum − 7) / 28 × 100
The grade sum runs from 7 (every grade a 1) to 35 (every grade a 5). We average desktop and phone, then the judge's passes, then the briefs, so every brief counts the same. The rescale is a straight line, so ranks and ties are the grade sum's own.
Every Index score carries an interval, and ranks come from the intervals.
A model grades the pages, so we check the model.
Run it twice, get the same answer. ICC is how closely two judge passes on the same page agree, where 1 means identical.
Grade sum ICC across two passes on 37 sites.
Grade sum ICC across three passes on 21 apps.
Grade sum ICC on 15 model-built pages judged twice. They sit close together, so passes swap them more often.
Average move in points when the same review runs again, from 96 reruns on real pull requests. About 9 in 10 land within 2 points.
The test that decides whether the number means anything.
A number people aim at gets gamed. These are the defenses.
Lines the measure never crosses.
Where the number can be wrong today, and what we do about it.
How a site, a lab or a team can dispute a score.
A score never moves without a line in a changelog.
Frameworks