Book excerpt: This book fills the gap in the literature on nursing theories by presenting the background information on situation specific theories such as philosophical bases and current status of situation specific theories and providing a collection of situation specific theories that have been developed. It provides specific guidelines for nursing research and practice, essentials for PhD and DNP students to complete the requirements for their degrees (e.g., dissertation, QI project). In addition, this book can be used in theory courses in other graduate nursing programs that require theoretical bases for their comprehensive exam or scholarly project (e.g., MSN, NP). Throughout nursing history, nursing theories have evolved within the contexts of changing and emerging theoretical needs of nursing discipline. Subsequently, several different types of nursing theories have been proposed, developed, and used in nursing education, research, and practice. Situation specific theories could be easily adopted and used in nursing practice and research due to their foci on specific populations or particular fields. Since situation specific theories were firstly proposed in 1990s, they became a major part of nursing theories in the past two decades, making this book appeals to all levels of nursing students.