This book contains a 1993 version of the Nutri-body Assessment program, which can be purchased online at http://rowlandpub.com/ordering.htm. I do not know if the on-line version has been updated from the original model, but I can speak to the version published in this book. It consists of many question groups, each of 5 or 6 questions in each area. The questions are basically about symptoms of illnesses that are related - according to the theory - to nutritional deficits or excesses.The questions are answered for each symptom as 'none,mild, moderate, severe' or 'none, seldom, occasionally, frequently' - although I don't remember the exact wording. Each set of questions is keyed to a specific nutritional issue and all must be answered to get the complete analysis and learn which questions are important. You calculate your scores and create your assessment. The book then provides information on interpreting your results, and taking actions that may improve your health.The survey is moderately effective in detecting and measuring fairly common health issues. In some cases, using only symptoms can easily lead in two - even opposing - directions. For example symptoms of overactive thyroid are very similar to symptoms of underactive thyroid. I am not a doctor and am not aware of any official scientific analysis of results or recommendations.The survey is quite long, and many questions are repeated several times, occasionally with small (insignificant) differences. It appears they were pulled from different medical textbooks and gathered into a single resource, without much though about redundancy - this was before computers were common. I would hope that, but do not know if the online survey has been updated and some of the redundancy removed. The book is based on our knowledge of nutrition and illness in 1993 - and there have been many new discoveries which might provide different results if it was updated.From a theoretical perspective, the book is - like most information about nutrition today - illness based. If you have no symptoms, or if your only symptoms are mild and infrequent, then in theory, you have no issues, and no actions can be recommended. Health is not accounted for, only symptoms of illness.The book is of historical interest, but I suspect that if you are looking for assistance with actual issues, you will be better off to head to the Rowland website.