Yesterday I wrote about two teams solving the same chart problem months apart. Suppose the mood team had written down what they learned. Would the sleep team have found it useful?
It depends on what they wrote.
"Charts must have a text alternative" is true and is useful as a rule. But it leaves many questions unanswered. The sleep team would still be wondering what to say.
So the artifact the team leaves behind should be more useful.
Imagine they distilled their decision into something like this:
We gave people a short summary so they could understand the pattern without seeing the line. We also kept the daily entries available as text, because the summary couldn't tell them everything. We tried listing the values alone, but it was hard to tell what had changed across the week.
Now the sleep team has a place to start. They know what problem the mood team was solving and why it chose that approach. Pay attention to the structure of the decision, what it contains and what it doesn't. It says what the problem they were solving was. It says how they solved it, how they reached that decision and why. It also says what else they considered and why they rejected it.
This is purely an example that would fit into a short email without taking over your inbox. But you can imagine these decision documents can, and should, follow a set structure and be as developed, and concise, as they need to be to keep the people reading it from guessing.
I know it's extra work, but that's how I approach things now. Every time we have to make difficult accessibility decisions, we write down what we chose and why so that the next team have something they can refer to, something they can use and something they can question if the situation changed.
Recorded decisions outweigh rules.