Is there a way to set the security on a survey that limits who is eligible to take it- for instance via the use of an id number? For example, if an instructor has 50 students in a class, but only 20 of the 50 students are eligible to participate in the survey, is there a way to limit the access just to the eligible ones. I'm asking because I want to ensure that if somone who shouldn't participate in the survey accidentally gets the survey link- they won't be able to participate even if they click on the link, because their id number is not in the pool of eligible participants .
FormsCentral does not provide any way to restrict access to the form.
The one option you have is to "embed" the form in your own website where you would have the required restriction in place on your own web page where the FormsCentral form is embedded. The embed code to embed the form is on the Distribute tab.