I run surveys on Mturk and I have two questions:
1. I use some standard attention filter questions to catch people who randomly respond to questions. The point is that if someone is not actually answering questions they shouldn't be paid. Since some filters are harder than others, and mistakes do happen, instead of rejecting work based on attention filters, I ask people to return the HIT when a filter question is failed. I received a nasty-gram recently saying that returning HITs is almost as bad as a rejection, and that it negatively affects their ability to do HITs in the future. I am not aware of any qualification that limits based on return rates, or of any way for a requester to access the return rate of a worker. Amazon told me that return rates are displayed to workers for informational purposes only, but I wanted to double check with the community. Does returning HITs negatively impact workers besides the unpaid time spent on the HIT?
2. I maintain an outside database of workers so that I can do custom qualifications without using the API. However, to see if a worker qualifies for my HIT, I need to look them up using their workerId. To my knowledge this is only accessable after a HIT is accepted. Is this true, or is there a way to access the workerId programmatically before the HIT is accepted. Second, if not, and if I wanted to avoid having people accept the HIT, find out they do not qualify and ask to return the HIT, is there a better way to get their workerId than asking a worker to type it in?