help + infinitive? - (Dec/14/2012 )

Hi!
Just a brief question for native (or proficient) English speakers:
Which is the correct form in this example?:

- This test may help define the general guidelines....
- This test may help defining the general guidelines...
- This test may help to define the general guidelines...

Thank you!

first ("to" is implied) and third look okay to me.

I think that the use of the infinitive (to define) and the bare infinitive (define) after help are both acceptable in this case so I guess it's a matter of which style you wanna use. The gerund (defining) hmmmm doesn't sound right. The gerund, I'd probably use in the negative sense- I can't help thinking, crying etc. For verbs of perception such as see, watch, hear, feel etc or causation- let, make, allow etc, the bare infinitives are often used....

Thank you very much!