This book on conservation abilities is part of a series designed to assist beginning and experienced teachers in becoming regular evaluators of their own instruction. The book consists of two parts. The first part provides information on: conservation related to number, length, solid amount, liquid amount, discontinuous length, area, weight, solid volume, and displacement. The second and far longer part consists of 10 self-directed and self-instructive workshops. The goals of these workshops are to: (1) use an assessment method to administer, at any grade level, diagnostic tasks to ascertain conservation abilities; (2) identify the developmental level attained by each student in terms of conservation abilities; and (3) select, from resources available, subject matter (content and manipulative materials) appropriate to the identified levels of development in students' conservation abilities. Except for the first workshop, the order in which workshops are completed or the number completed are at the discretion of the teacher. A short review of some research on conservation abilities, a bibliography, and sample forms used to record students' conservation abilities are included. (JN)