Research & Insights

By John Horton, February 27, 2010

Why People Participate on Mechanical Turk, Now as a Mosaic Plot

“Who are these people?” and “Why do they participate?” are two perennial questions about AMT. Askers are generally incredulous that AMT workers are willing to do rather tedious tasks for small amounts of money.

To investigate this question of motivation, NYU Prof. Panos Ipeirotis asked a bunch of workers their reasons and tabulated the responses here. His two posts are actually on the syllabus for a course at Stanford (incidentally the course is taught by one of the creators of Protovis, which is very cool and is on my list of things to learn). There is also this amusing investigation.

For a joint project with Dave Rand and Richard Zeckhauser, we asked ~ 400 AMT workers both (a) where they are from and (b) the primary reason they participate on AMT. Because economic opportunities differ by country, we might expect that motivation and behavior should also differ by country. The cross tabulation plot is below (reasons are in the “rows”, countries in the “columns”–the size of each rectangle is proportional to the number of responses in that cell):

country_motivation.png

Two things to note:
1) Money is a big motivation for everyone
2) Money aside, people from India are there to learn; people from the US are there to have fun

Although the India/US differences are consistent with the different-countries/different-motivations hypothesis, the most relevant fact is the unconditional importance of money.

While these findings seem reasonable, I feel compelled to make the standard reliability critique of self-reported data. Our learning/fun AMT workers might also be there for the money, but feel sheepish about saying so. Though this could go the other way as well I suppose: if, for example, a worker has an intrinsic love of image captioning but finds this passion shameful, they might report that they are in it for the money. But this seems less likely than the other scenario of downplaying financial motivations.