What association do I need?

Hi

I'm a little confused as to what kind of association I need for this structure

I have the models user, task and logs which all can have associations to some models which can be put under the loose heading of tests, the problem is that the test models have to be different models as they contain vastly different data and behaviour eg, a iq test, reaction test, personality test.

I thought that the best approach would be to use a polymorphic association so that I could do something like user.tests, task.tests, log.tests and also user.iq_tests etc but I'm not sure how I go about this as all the examples I've seen so far deal with one record having a single association with multiple types of model like have a single comment model being able to be linked with Post User or Photo and I'm not sure how to go from that to what I need

I've also seen a plugin which appears to deal with the type of thing that I want here http://github.com/fauna/has_many_polymorphs but as I dont know enough about polymorphic associations I have no idea if this is needed for my particular scenario

Can anyone advise me on this?