Hi
Lots of people get intimidated by the activation step, but you need to remember the NOPS formula. 
Play around with it...you don't have to get it right the first time, you know. The more familiar you get, the better. You'll find that it gets easier.
You finish activating when the information has "gelled". This is when your comprehension has reached a critical point, and can come quite suddenly during the activation process - you suddenly realise you know all that you want to know. Since you say your purpose is clear, you ought to be aware when your comprehension reaches the gel point - everything you need to accomplish your purpose is there! Gelling for you can be different from gelling for someone else because we all have different purposes for reading.
Thirty-minute sessions are extremely helpful not just in making the activation sessions seem less intimidating, but also because your brain tends to slow down after roughly this amount of time. A short break perks it up again. Also, having to cover material in a given amount of time ensures that you are not overdipping and pushing into rapid reading too early.
You can try letting information come, though that is somewhat less reliable than manual activation. You might want to read up on direct learning if you're hoping for spontaneous activation. I suggest you work on manual activation first. After awhile, you'll probably experience a few spontaneous activations anyway.
One way of keeping track of the triggers is to start using them on a mind-map immediately. Thus, your triggers are always on the mind-map. A little filing also helps. 
Hope this helps.
KWLee
[This message has been edited by KWLee (edited November 30, 2002).]
