Why does the size of an EOLSS chapter vary?
The chapters are at THREE or TWO distinct levels as indicated by the color of its title (see the related chapters). Level 1 (Theme Level): A chapter at this level introduces a core subject (or a field of knowledge) to a wide audience including undergraduates and non-expert readers needing to grasp the fundamental concepts. These chapters generally avoid the use of technical jargon or complex mathematics. Level 2 (Topic Level): A chapter at this level introduces a branch of the core subject (or a sub-field of knowledge) to be covered by a group of Level 3 chapters. The contributions are useful to senior undergraduate and postgraduate students as advanced study cum reference material. Level 3 (Article Level): Most of the contributions in the EOLSS are at this level. These chapters cover different aspects of the sub-field in depth and contain relevant and necessary details of the established knowledge associated with it Therefore the size of the chapters varies depending on the scope and
