Each entry has two parts; a concise dictionary definition and an expanded description which more fully explains each term or concept The dictionary has a selection of `commentary pages', specially written to explain more complex issues in context Diagrams and charts are included wherever they can help a student's understanding Students are referred to other words which may help their understanding of a term or concept. UNIQUE: each entry has two parts; a concise `dictionary' definition and an expanded description which more fully explains each term or concept COMMENTARY PAGES: the dictionary has a selection of `commentary pages', specially written to explain more complex issues in context ILLUSTRATIONS: diagrams and charts are included wherever they can help a student's understanding CROSS-REFERENCES: students are referred to other words which may help their understanding of a term or concept