This text focuses on one important aspect of psychological research - the intensive study of people measured one or more at a time. Some important historical material is detailed in several chapters making a connection to previous material in psychology. Several contributors present important details on classical and novel methods to study behaviour over time, and they do so in the context of appropriate statistical methods. This reflects the growing interest in examining dynamic behaviours by objective behaviours by objective measurement. Key experimental design principles are expertly stated, reflecting the growing interest in studying the individual course of development for invariants in behaviours, including some unusual constructs such as cycles and punctuated equilibria. This book also deals with practical contemporary problems in psychology and documents the increased possibility of using clinical research tools. Taken as a whole, this volume is filled with historical points, informative mathematical and statistical analyses, and practical methods. It addresses the issues of meta-analysis, cyclicity and confounds to visual inspection of single subject data that considers ways in which statistical software can aid in overcoming these constraints.