This book is the most popular version introducing the approaches and principles for validating Lot Quality Assurance Sampling (LQAS) Method. The LQAS method was first developed as a quality control technique for goods produced in factories in the 1920s.It gained popularity during Second World War when it was used as a method for improving the quality of war materials. since its introduction to public health in mid - 1980s, the LQAS approach has been used to assess measurement for growth monitoring programs among others.