In 2013, three Harvard researchers decided to see how different levels of pay would affect the amount of work they got.
On the freelancer contracting site oDesk, they posted jobs typing in CAPTCHAs, those hard-to-read words or codes used to authenticate that a real human is accessing a website. "This is a four-hour job, with the goal of entering as much data as possible while minimizing the number of mistakes," stated the postings. "Specifically, we need as many correctly entered words as possible in four hours because we need the data for a future task and only correct entries can be used."
