The scientific discipline of clinical psychology has witnessed paradigm changes in the prevailing conceptualization of psychopathology and in the rigor of experimental methods to test psychosocial treatments. In parallel, neuroscience approaches to mental illness have become increasingly prominent and technologies to measure psychological constructs over time and across contexts are becoming ubiquitous in psychological research. Altogether, these changes have pushed clinical scientists to incorporate novel research methodologies and analytic approaches. Modern studies of clinical phenomena are often theoretically integrative and assess constructs across levels of measurement, ranging from the molecular to the behavioral. These shifts are fundamental, and necessitate changes in the way modern clinical psychologists design studies, collect data, and draw scientific conclusions. This book is intended to serve as a guide for the next generation of clinical psychologists, who will benefit from greater training in statistics, study design, developmental psychopathology, and multimethod approaches.