He expects you to know principles such as quick development, castle quickly, don't move you're queen etc. If you are rated 1500 FIDE/USCF you definately should know this.
Actually he doesn't, he states the basic opening principles at the beginning of the chapter as if it was new material for us to learn. Then he proceeds to give test questions that are not even remotely appropriate for the level indicated.
Eric Schiller is a FM
http://www.chess.com/coach/fmericschiller
His books are often slammed by higher rated players, but IMO his target audience is your average player. I have had mixed experience reading some of his books, some I have really enjoyed and others leave me shaking my head. I believe he is the Fred Reinfeld for this generation.
im not convinced of Eric Schiller but what do i know....