Then why does the IRB exist? :) How were you able to draw a distinction between your consulting assignments? QED

> When I worked in my university’s statistical consulting center in graduate school I could have consulted on the same experiment either subject to IRB or not depending on who the client was.

(emphasis added). Somehow you misread it.

I did have a similar job for 2 years (statistics assistant farmed out to help out on different grants as needed), but clearly not long enough.

I'm a bit flummoxed, though. I had the very distinct impression an IRB imposes certain requirements.

I shouldn't even call it an impression, you're aware of it too.

Like, an experiment under the IRB has certain tasks others don't.

I don't understand what I'm missing or what's missing in our communication here.

I almost called up an old prof to ask but any question I could think of, I sound high ("does an IRB supervised experiment have different requirements from, say, a city changing traffic light timings on a street?")

Are you just trying to say in theory an IRB could always impose no requirements other than talking to the IRB, and the IRB considered human subjects and say "go ahead, ethical"?

Note that's still a distinction. FWIW that doesn't happen in tech, no IRB, no reviews of experiments. Infamously this caused some issues at Facebook