I’m not sure what I’ve done differently, but my under screen reader on my 6 pro is more reliable than the back reader on my pixel 3.

Obviously my one data point doesn’t negate the vast swathes of people who do have issues, but for me I may not even elect to use face unlock. Seems unnecessarily insecure.

In statistics, everything is based off probability / likelihood - even binary yes or no decisions. For example, you might say “this predictive algorithm must be at least 95% statistically confident of an answer, else you default to unknown or another safe answer”.

What this likely means is only 26% of the answers were confident enough to say “yes” (because falsely accusing somebody of cheating is much worse than giving the benefit of the doubt) and were correct.

There is likely a large portion of answers which could have been predicted correctly if the company was willing to chance more false positives (potentially getting studings mistakenly expelled).