Functional analysis methodology focuses on the identification of variables that influence the occurrence of problem behavior and has become a hallmark of contemporary approaches to behavioral assessment. In light of the widespread use of pretreatment functional analyses in articles published in this and other journals, we reviewed the literature in an attempt to identify best practices and directions for future research. One of the book’s key strengths is its emphasis on clarity and simplicity. Functional analysis can be an abstract and challenging subject, but Nair manages to break down even the most complex topics into understandable and digestible sections. Theorems and proofs are presented in a logical and accessible manner, with ample explanation and examples to support the development of concepts. The step-by-step approach ensures that the reader is guided through the material in a manner that encourages deep understanding rather than mere memorization.