Mechanical Turk Workers Are Not Anonymous
crowdresearch.org
crowdresearch.org
These days Turk goes so far as to handle your 1099s for you - so you don’t know the names of even the workers that have done more than $600 worth of work for you…
Of course most employers in it for the long haul build up reputation databases built on these ids, and many encourage their workers to fill out profiles, direct on the employers website, allowing for more direct contact, and less constrained messaging.
Which is why this is a big deal for the employers: names, pictures, locations, and review helpfulness, can all be shoved into the reputation algorithm or used by survey companies for demographics. So it will be harvested.
And that makes turk a lot less anonymous. Which seems like a breech of trust to the workers, because although they aren’t guaranteed anonymity in the TOS, that has been the bargain so far.
By choosing to use Amazon IDs as worker identifiers, Mechanical Turk gets all of the disadvantages of having anonymous strangers do jobs on the web -- lack of accountability, diminished incentives, malicious workers -- but none of the advantages of protecting workers, since at the end of the day, they're not actually anonymous anyway.
This is a non-issue in MobileWorks (and for that matter, oDesk and Freelancer as well). In these systems, everyone's explicitly working under a real name, which improves incentives to perform well, and makes it a whole lot easier to get good results through trust and honesty.
In this case, as the experiments involved people and the intend was to publish the results, the "workers" had to be anonymous.
This is why we created http://SocialSci.com for use by academic researchers: We have better control over PII outside the Amazon ecosystem, and access to more data we can take our own steps to protect or de-identify, enabling higher quality data collection.
In general academic research done on Mechanical Turk has a ton of issues, from response quality to verifiability of responses. Frankly people have no incentive to remain authentic across surveys, and we've seen cases of people just taking on identities or just faking answers, which isn't reliably detectable. The only way we've been able to overcome this is by tracking users' response consistency over time, and keeping them anonymous in the process. It's proved to be a much more reliable method, and at this point based on our experience we can't recommend MTurk for valid academic research.
We don't claim to entirely prevent fraud, but we're very confident that we raise the barrier and reduce the rate significantly.
Edit: The closest thing I found was that you can't create tasks that involve "collecting personal identifiable information". I would think that is aimed more at preventing tasks that are essentially selling your info for the price.