[jwx48]

Litter box cleaner: A kinect, a digital weight scale, a couple of cameras, a robot arm, a litter box, an internet connection and I would pay 25c for people using Amazon's Mechanical Turk to manipulate the robot arm and clean the litter box for me. And people would wait in line to take the job.

This blows my mind, and I love it. What sort of limits did you put on the Mechanical Turk service to keep people from farming the... you know... turds.

[justinlloyd]

It posted a MT task when it detected weight in the litter box that was less than a cat but more than a little pee. Very sensitive digital weight platform and some fine tuning of the heuristic to get it just right. Then the MT task had to be finished in X minutes from when they start, but the Turker could request extra time on the task. But if they didn't, it would time after N minutes. Then, if they have clicked "done", two more MT tasks would get generated for two new people, where the MT worker would be asked to look at a before and an after shot of the litter box and decide if it was clean.

I kept it online for about six months. It was obviously a "dumb idea taken to the extreme" project, which included "and what can I do with computer vision and robotics for my final project with this really expensive Fujitsu robot arm I picked up from a surplus auction?"

You may be referring to the "farming" to be first in line to get the job. I didn't really prevent anything like that. Cats poop at different times, so no real way to predict when the job would pop up on MT. The Kinect and weight sensor in combination determined there was no cat present, and then the job would post. The job would always be gone in seconds. People got very creative with their cleaning, treating it like a Zen sand garden. I would come back and see pure art at times. Once, the MTurker stacked up the excrement like they were recreating the mashed potato scene from Close Encounters. They were not invited. Much like the popular meme: "Except for Billy. Billy has created the opposite of art."

I did have the usual "if the person who cleaned it last didn't do a job that passed review, they would be barred from taking future cleaning jobs."