This book aims to introduce students to the process of assigning and especially synthesising class numbers by the 19th edition of the Dewey Decimal Classification (DDC-19). It is still the highly used edition in Indian library schools.The chapters and the examples have been graded to some extent. No background, whatsoever, has been assumed on the part of the students. It provides a complete course to train them in the techniques of number building involving the use of auxiliary tables and multiple synthesis.The graded process of number building will show the students the increasingly faceted nature of the system and its advancing steps towards what S.R. Ranganathan terms as depth classification. To avoid verbosity, the number building has been depicted through equations and facet formulae. The examples chosen are, as a matter of necessity, largely imaginary, though not far from the realities of the literary warrant. The aim is to be amply illustrative and to step by step introduce the new concepts and methods. ‘ Though the book is based on the 19th edition of the DDC, students using the DDC-18 and 20 should find no difficulty in using it as there is not much difference between these editions. Last chapter briefs the students on the current trends in the DDC studies and research.
