Factors include: how well you have mastered PhotoReading, what is your purpose, what level of familiarity do you have with the material, how confident are you with your skills or the subject, how do you feel today, what's the weather like, how relaxed are you...
I can go through most nonfiction books on the bestsellers list in thirty minutes. I'd do quite well on a comprehension test.
I've demonstrated on television going through bestsellers and immediately answering questions. I use the questions as the activation. I'm not fond of that much pressure. I prefer other forms of activation.
When a book is written for someone who has substantial background in a subject, I syntopically read 3-5 books on that subject. This helps me get a base understanding more quickly, generally, then just the first book. (This is described in the PhotoReading book.)
I haven't done a biochem book since college.
My advice: play with it. See what results you get with the system. See how you can improve your performance. Be willing to fail. Just like a kid. That's when you will shine.
PhotoReading is a different paradigm then regular reading, but it is effective.
