Explain how the simultaneous and batch limits work

[mizzao]

From Nasrin:

When I create a new HIT (from a HITType) each user can only do the HIT once (however, we clearly want one user to do many of these conversations). In Mturk one can instantiate a batch of HITs from the same HITType (in which case you need a csv data file), so that the same user can have as many submissions as the number of HITs. How can I do that with Turkserver? I can imagine creating a new HIT again and again, but then we’ll have many tasks as opposed to one task on MTurk’s page. Also I don’t know what will be the implication of having multiple HITs per HITType, we don’t want the same user to go and pair with herself!

My response (to be fleshed out and added to the docs):

Right, a HIT with many assignments only allows each user to do the HIT once. If you create multiple HITs with, each user can do the HIT up to as many HITs as you have created (and you save some money if you create less than 10 assignments per HIT.) Creating multiple HITs under one HITType does not result in multiple different tasks on MTurk.

TurkServer has some safeguards during this process, though: by default users can’t accept more than 1 hit at a time (this prevents them from pairing with themselves, “banking” HITs, or doing multiple interactive tasks simultaneously.) There is also a limit on the total number of HITs they can do. Often I set this to 1 as well when I have long-running tasks that require unique workers, but you can set this to whatever number you want and a worker will be able to come back up to that limit. These are controlled by the software on top of what MTurk already provides, and you can test this in the sandbox.

To control these values, set them in settings.json: https://github.com/VirtualLab/turkserver-meteor/blob/master/server/config.js