This mograph provides an overview of recent developments in and new applications for multimial processing tree (MPT) modeling in cognitive psychology and related fields. Multimial models are a class of stochastic models tailored to specific research paradigms that allow the measurement of latent cognitive processes underlying observed responses. An introductory review and literature survey in this mograph outlines the family of MPT models, the typical steps in MPT model analyses, the use of MPT models in cognitive psychology, statistical considerations, and computer programs for MPT modeling. Original research articles then present vel MPT modeling approaches in different fields, including episodic memory, binary choice models and 'guessing', and word identification in early reading. Discussions of matters such as cognitive psychometrics and ongoing developments of MPT modeling throughout the contributions clearly demonstrate how active this field of research is and the wide range of applications of multimial modeling. The Zeitschrift fur Psychologie, founded in 1890, is the oldest psychology periodical in Europe and the second oldest in the world. It will w, with a change in language to English, be published as a series of mographs on basic and applied topics in psychology, each featuring a major overview article, peer-reviewed original research papers, as well as brief 'Research Spotlight' and 'Horizons' reports about ongoing or forthcoming projects. Each carefully compiled mograph is edited by leading experts and features articles by scientists at the forefront of current research.