Exactly.
I didn’t check the math or specific assumptions, but this is a hypothesis test:
“Under the null hypothesis that Tesla robotaxi has the same accident rate as the average human driver, what is the probability that I would observe 3 accidents?”
(depending in your exact null hypothesis “Tesla’s rate is the same or lower than a human”, often you would calculate the p-value, the probability of observing an event as or more extreme (in the larger direction) than the 3 events you observed, so the total probability of 3, 4, 5, …, etc accidents in 7k miles)
That’s why people should think carefully about what is typically a rare event (ballpark 1 accident per million miles, but very dependent on exact driving scenario) and then what it means when
- we don’t observe any events over few miles (10s of thousands) versus
- we do observe accidents over few miles
The former doesn’t tell us too much about Tesla’s rate, other than “it’s not super large.”
The latter tells us with much more certainty “it’s not small.”
Again, I think the above reasoning has been communicated in a few threads.
So that’s why when people make small sample statements “It drives great for me.”
Or statements like:
They should think about the reasoning above when we repeatedly observe events like the rail crossing
and many others that have been documented, like this one: