This book is a natural step beyond our earlier text A Teacher's Guide to Assessment, which was published almost six years ago. The purpose of this book is to offer a straightforward guide to educational assessment for teachers at all levels of education, including trainers and instructors. The scope of this book is wider, however, and the targeted audience is broader than the first edition. It is designed to address the needs not only of those taking a first course in educational assessment and measurement but it can also usefully serve students at the post-graduate level, as well as experienced teachers, trainers and instructors who would like to update their knowledge and acquire practical skills using relevant quantitative methods. The book is appropriate for an international audience. In this revised edition we have added new and important material which covers the assessment arrangements necessary for people with special needs and the use of technology for assessment purposes. We have elaborated on the dangers of differential item functioning; we have extended the Rasch measurement material; and enriched the book with practical examples using Microsoft Excel. The main message of the book is that assessment is not based on commonsense but on a huge body of international research and application over many years. Testing is a powerful, vital and large part of a teacher's assessment arsenal because it can be practical, structured and very informative. The correct use of testing, either in its traditional paper-and-pencil form or in its modern technology-based style can be a formidable ally for every teacher who aspires to practise evidence-based teaching and learning.