I'm very new to Mturk and will be posting my first survey. I want to have a few questions at the beginning that I'll pay turkers to answer, then if they qualify give them access to more questions for a higher price. I was thinking that I could have a single hit with a survey that terminated with one set of codes if folks only made it to the prescreen, but let those who qualify keep going and give them another set of codes to get the higher pay. Of course, I would articulate this all in the hit description so that people would know what they were in for. Has anyone done this before and does this sound like a workable system? I am not a programmer, so don't see myself programming qualifications. Thanks for an advice you can spare!