Very likely the single most important feature this book offers is exactly what we word-hunters mostly want from a thesaurus: an impressively high hit rate and a large number of highly useful references. Besides that I think this book excels its competitors (painstakingly compared trying to buy the very best available one) in many another important ways. Other thesauruses and even some children's dictionaries' "how to use" sections run for several pages in rather small typeface. The fact that the "How to use" section of this thesaurus takes really sparse areas of the front and back pages of one single leaf can give you an idea of how easy to use it is. The backbone of this ease of use of course is the thoughtful organization. The book (1415 pages) is divided into two main parts: the thesaurus itself and the index. Want to look up a word? Look it up in the neat looking 4-columns-per-page index (40% of the book) which is guaranteed to contain an entry for every single word and phrase contained in the book. There you get the keyword and number of all the different subparagraphs in the thesaurus where that word appears. These numbered paragraphs group together words of similar meaning. The paragraphs are subdividions within parts of speech (nouns, adjectives, verbs...) within numbered subcategories of the top 24 large groups of related subjects embodied in the thesaurus. At the end of each paragraph you may also find very useful cross references to other related categories. What if you have a tip-of-the-tongue effect or don't really know the word you want? Then you could navigate through this really easy to follow hierarchy of subject, category, part of speech and then numbered paragraphs, and enlighten yourself finding as many relevant words and cross references as there may possibly exist within the given domain and subcategory you are interested in. Alphabetical and order-of-appearance indexes are provided for all the subject categories. Quotes are also provided showing how heading words are used, and also special listings that amplify the textual paragraphs. But still besides this impressive hit rate and the wise and easy organization, being a computer scientist and software developer aware of user interface issues -and being a book worm myself- I think the making of this book also excels its competitors in features frequent users and book lovers greatly appreciate: the quality of the paper (clean white), the clarity and readability of the typeface, and the thoughtful and consistent layouts (even minor details like how the ranges of paragraph numbers and keywords stand out over the page numbers at the bottom of each page). I think this book is surely the best in its class for those several reasons. What is more, I think it's not just a highly valuable reference tool for native English speakers but particularly for anyone studying or using English as a second language (like this reviewer), and in general for anyone trying to improve their vocabulary.