[cm2187]

The buses and fire hydrants are easy. It is the bicycles. If it goes a pixel over the next box, do I select the next box? Is the pole part of the traffic light? And the guy as you say. There is a special place in hell for the inventor of reCaptcha (and for all of Cloudflare staff as fas as I am concerned!)

[charcircuit]

It doesn't matter. Select it of you think other people would select it too.

[cm2187]

That's the thing, you could go either way. I am not sure I can answer the question "what would a resonable person click?".

[jorvi]

The trick is to pretend you're an idiot. If the bicycle and the person on it map mostly to a rectangle of 8 squares, most people will be so stupid or hasty that they'll click that, nevermind that a human is not part of the bicycle.

The same is true with, say, buses. See an image of a delivery van? Bus! It asks you select all cars and you see no car but a vague pixel blob that someone stupid would identify as a car? Car!

One of the few things that this doesn't work with is stairs, because the side of stairs being stairs or not is something apparently no one can agree on.

[abacadaba]

Answer how you'd want a Waymo to react

[charcircuit]

If it can go either way then you can pass the captcha either way too. There isn't a single correct answer to these captchas.

[timshell]

The 'Process Turing Test' extends the CAPTCHA from 'What would a reasonable person click' to 'How would a reasonable person click'.

For example, hesitation/confusion patterns in CAPTCHAs are different between humans and bots and those can actually be used to validate humans

[dfxm12]

There's not a right or wrong answer. They're just building consensus for self driving vehicles.