"Power analysis is vitally important for designing strong studies and convincing grant panels that a study is fundable, yet it is rarely (if ever) part of formal quantitative methods courses or training sequences. This book empowers researchers by providing an accessible explanation of Monte Carlo approaches to power analysis, which are particularly useful for modern, mainstream multivariate statistical models popular in the behavioral sciences. The book walks through the mechanics of Monte Carlo studies and deftly explains how to write corresponding code in Mplus and R, interpret the output, and understand implications for sample size. This is an indispensable resource for behavioral scientists and methodologists seeking to design studies and craft effective grant proposals."--Daniel McNeish, PhD, Department of Psychology, Arizona State University "This book fills a critical gap for researchers. Typical textbook examples for power analysis usually refer to relatively simple models with complete data sets, whereas the reality of models and data is often much messier. The topics and simulation approach outlined here addresses this reality, by providing researchers guidance and accessible software to run Monte Carlo power analyses for complex models with multilevel and missing data. Using this book, research faculty and graduate students alike will be better equipped to conduct more solid research and to write grant proposals with more realistic sample size estimates.

"--Fred Oswald, PhD, Professor and Herbert S. Autrey Chair in Social Sciences, Department of Psychological Sciences, Rice University "Power analysis is essential for designing robust and replicable studies, yet it can seem daunting and complex. Peugh and Litson demystify the process, offering a step-by-step guide that encourages researchers to engage deeply with their data and avoid the pitfalls of underpowered studies. The included Mplus and R syntax go well beyond basic models, and the authors' clear explanations make simulation-based power analysis both approachable and immediately applicable."--Francis Huang, PhD, College of Education and Human Development, University of Missouri-Columbia.