This book focuses on the crucial theme of modern test development and analysis, specifically focusing on bridging the gap between theoretical frameworks and practical applications. This resource offers a practical and detailed exploration of psychometric principles, encompassing both classical test theory (CTT)-based item analysis and item response theory (IRT), specifically focusing on the one-parameter model (Rasch model) for test equating. By considering CTT and the more sophisticated Rasch model, the book provides a comprehensive pathway to enhanced measurement accuracy and efficiency in the human sciences. It aims to empower readers with the tools and knowledge necessary to navigate the complexities of test equating, item bank creation, and the implementation of computerized adaptive testing (CAT). It provides historical context for these methodologies and outlines prospects for Rasch research, emphasizing the importance of establishing a common scale for measuring ability. A significant contribution is the introduction of Rasch-GZ, a cutting-edge software developed during the COVID-19 pandemic that incorporates AI-driven assistance and bilingual support, potentially streamlining the calibration process of items within an item bank. The book thoroughly reviews fundamental concepts such as item difficulty and discrimination, ensuring readers grasp the theoretical underpinnings of both CTT and IRT. It delves into various test equating techniques, including Common Item Linking and potentially Common Subject Linking, crucial for maintaining invariance across different test forms within a Standardized Examination. Real-world examples with detailed interpretations serve as a step-by-step guide to these procedures, often relying on anchor items. While implicitly addressing the concept of the norm in the context of standardized examination interpretation, the resource primarily focuses on the application of psychometric software. Access to the student version of Rasch-GZ is provided through code, alongside supplementary video tutorials, facilitating hands-on learning and software mastery. This book could be used by practitioners in the fields of applied linguistics, applied psychology, language testing, education management, and researchers working on language testing methods.