This is one of the most beautfully written texts in the experimental analysis of behavior.    In his own words, "the conception of experimental methodology I advance is not a set of rules of experimental procedure, to be memorized from a textbook."  Sidman emphasizes the importance of replication, variability, recognizing trends in the data and the ability to alter the experimental design in response to these conditions and not to undertake a ridigidly designed experiment based upon a preconceived notion of what it should reveal.
Paperback, some study notes; good condition.