Behaviour analysis emerged from the nonhuman laboratories of B. F. Skinner, Fred Keller, Nate Schoenfeld, Murray Sidman, James Dinsmoor, Richard Herrnstein, Nate Azrin, and others who pioneered experimental preparations designed to do one thing - find orderly relations between environment and behaviour. This bottom-up approach to a natural science of behaviour yielded a set of behavioural principles that proved orderly and replicable across subjects, laboratories, and species. By the 1960s, behaviour analysts began translating these principles into interventions for institutionalised humans characterised by impoverished repertoires of adaptive behaviour. When these interventions proved successful in replacing problem- with adaptive-behaviour, the field of Applied Behaviour Analysis was born. Over the last 50 years the field of behaviour analysis has grown substantially both in the number of practicing behaviour analysts and the range of behaviour to which behavioural principles have been applied. Today the laboratory study of basic principles of behaviour continues to expand our understanding of behaviour and to inform the treatment of disorders ranging from autism to substance abuse. The present volumes continue this inductive translational approach to the science of behaviour analysis by providing overview and in-depth chapters spanning the breadth of behaviour analysis. Volume I: Methods and Principles provides comprehensive coverage of the logic, clinical utility, and methods of single-case research designs. Chapters walk the reader through the design, data collection, and data analysis phases and are appropriate for students, researchers, and clinicians concerned with best practice. Volume I also provides an overview of the experimental analysis of behaviour, and chapters reviewing some of the most important areas of contemporary laboratory research in behaviour analysis. Topics covered include memory, attention, choice, behavioural neuroscience, and behavioural pharmacology. Volume II: Translating Principles into Practice includes 10 chapters illustrating how principles of behaviour discovered in basic-science laboratories have provided insights on socially important human behaviour ranging from the complex discriminations that underlie human language to disorders treated by clinical psychologists. The second section of Volume II includes 12 chapters, each devoted to a particular behavioural/developmental disorder (e.g., behavioural treatments of ADHD, autism) or to behaviour of societal importance (e.g., effective college teaching, effective treatment of substance abuse). Each of these chapters provides a review of what works and where additional research is needed.