I was talking with Marco yesterday about the possibility of the user's triggering multiple interventions as they type a query string. The example I gave is that when I type "firefox cres", we show the update intervention. Then when I type a final "h", we show the refresh intervention. It's a little surprising that we show the update intervention for "firefox cres". "cres" is an edit distance of 2 away from "free", which is an update keyword. So the total edit distance of "firefox cres" is 2, and divided by the word count (2), the final mean distance is 1, and that's why we show it.

I think we should tighten this up by requiring each word in the query string to have <= 1 distance, instead of the final mean distance <= 1.

It would definitely be nice if the linker automatically flagged for feedback or NI. Maybe we can talk to Peter about that, but I bet you're right that it's not easy.

I merged the PR, so I'll close this.