Assessment, mainly in the form of tests and examinations, plays a critical role in the schooling of Singaporean students. The results are often used to make irrevocable decisions on the students' future education careers. This book is written with school leaders, teachers, and parents in mind, with the view of helping them to better understand the processes and products of assessment via tests and exams. It is written in simple terms, using minimal technical terms, and introduces school leaders, teachers, and parents to essential concepts and principles of educational measurements which are relevant in the school context in Singapore. While existing books on educational measurement are academically-oriented and meant for formal training courses, this book makes self-study simple by using practical examples couched in layman's language. In addition, this book uses concrete examples and analogies to make the text reader-friendly.