I find book tests a little too complicated. Alvo said this on his blog which I agree with wholeheartedly:
"The truth is, I've never really liked "The Book Test" as traditionally done for a variety of reasons:
The mentalist usually provides the book.
Usually only 1 or 2 books are used.
Usually a book I've never heard of, or one that's 100 years old.
Sometimes the mentalist has to handle the book.
Finally, why are you using a book to simply "think of a word?" As my friend Luke Jermay likes to say, "I already know thousands of words." Why even use a book?"
That's true, I prefer to do a book test as a memory affect, I either speed read or provide a book which I claim to have memorised. I then ask for a page, line and number of the word on the line. I'd rather not do it as a mind reading stunt, I'd simply prefer to let the spectator pull a word out of thin air. Anyway the book test is less important than the device which makes it possible, which is what I was inquiring about. If something is coming onto the market that's new and direct I'd love to hear about it. Just hold off on all the marketing spiel please. I hate hearing the words "revolutionary new technique/ gimmick" it always sets me against something.