anthropology at Stanford University and raised and working in Switzerland, had achieved of the fundamental aspects of molecular biology. Impressed also was I by the message (one rarely heard publicly) that the humanities have expectations that biochemistry and molecular biology will be able to o!er clear molecular explanations, not just of basic life processes, but especially of all aspects of our mental activities, normal or drug-induced. The origins of knowledge that this book is about are those insights about nature that are contained in the hallucinations (in more traditional terms &visions') experienced by shamans in many cultures, but especially those of Amazonia, where they are induced by drinking brews derived from tobacco and aya- huasca. Nicotine and N,N-dimethyltryptamine are the main active ingredients, respectively, of these two brews. The former is hallucinogenic (or in classical terminology &entheogenic') only in high doses, the latter is much more active and is also produc- ed normally by the human brain. Narby reveals intriguing correspondences between the world of shamanic knowledge (commonly expressed as cosmic ser- pents, twisted snakes, ladders, spiral staircases, braided ropes or vines, etc) and that of molecular biology (commonly represent- ed by double helical DNA, the common foundation in living organisms and all their forms). His personal adventure, lasting some ten years, to seek explanations for the images, metaphors and stories of shamans (drug-induced or not), wonderfully brings together psychopharmacology, mythology, cultural an- thropology and molecular neurobiology. He achieves a syn- thesis of signi"cant proportions that is presented as a bold and far-reaching hypothesis. His scholarship (there are nearly sixty pages of notes, mainly on molecular biology and related topics, and over twenty "ve pages of bibliography) is deep and his writing clear and imaginative. If you, or your students, feel a need to explore the wider rami"cations of DNA in your brain cells and its possible role in generation of important historical symbols and metaphors, this book is for you. I suggest that you "rst read it as individuals to familiarise yourselves with the arguments presented, then come together to analyse, discuss and critique them in depth. Having done that, see the powerful e!ect the book has on both of you as your horizons expand and exciting new vistas and understand- ings arise. Two very di!erent ways of knowing, frequently thought of as being mutually exclusive, start to overlap and to enrich and illuminate each other. Believe me, I have no regrets in buying and reading this book. F. Vella PII: S0307-4412(99)00045-X Planning and Implementing Assessment ; R. Freeman, R. Lewis (Eds.); Kogan Page, London, 1998, 318 pp. ISBN 0-7494-2087-1, &19.99 The authors of this book intended to be both authoritative and full of practical ideas. The book covers the principles of good assessment and the kinds of practice to which these principles should lead. It is indeed very comprehensive for a text on assessment with chapters and/or sections on the purposes of assessment, the principles of assessment, norm versus criterion referenced assessment, issues of reliability, validity, a whole chapter on the de"nition of assessment criteria and another one on giving feedback, as well as extensive dis- cussions of techniques. In general, the book is clear, well struc- tured, and has myriad examples and summaries so that key action points are included at the end of each chapter. There is a very useful list of about 110 references at the end of the book, although some important ones in both general and medical education are excluded. For example, the excellent review of research by Wood (1991), Cambridge University Press, and the volume by Case and Swanson, published by the National Board of Medical Examiners, on designing written items. Nevertheless, a great many things are included and discussed well. My main problem with the book lies in its use of rather poor examples for illustrating points. This is particularly true of the very di$cult area of writing good objective items. Many of the examples are &what not to do' rather than &what to do', which makes one wonder whether the authors have a sensible batch of items that they can call on at all or whether they personally, in general, avoid writing objective tests like the plague. Hence, as an illustration of &rule 5' in multiple choice questions, &&distrac- tors must be plausible'', they quote the following example: In the following question, there is really only one key and two distractors, no one would ever choose option B. In a double rainbow, which is the innermost colour of the outer rainbow? A Red C Violet B Black D* Blue Similarly, in discussion of the next rule, &avoiding all of the above and none of the above items', both examples given commit the fault and no item is included that replaces one of the rogue options with a sensible alternative. Similar problems occur in their discussion of true/false questions where they suggest changing the item &&pubs serve beer and wine'' true/false? into three separate questions which, when presented together, are fatally #awed. The book also ignores the psychometric aspects of assess- ment, particularly the establishment of con"dence limits around scores * the standard error of measurement * and the problems surrounding combining scores from di!erent types of tests. Both of these are key issues for many examiners. In summary, this is a useful and almost comprehensive book which probably needs to be supplemented with a few other specialist volumes in order to solve particular problems. For the general lecturer in a Science department looking to improve their knowledge and use of assessment, they could do a lot worse than start here. B. Jolly PII: S0307-4412(99)00047-3 What’s the Use of Lectures? Donald Bligh (Ed.); Intellect Books, EFAE, Earl Richards Road North, Exeter EX2 6AS, UK, 1998, 316 pp. ISBN 1-871516-79-X, &14.95. e-mail: books@intellect-net.com; Web address: http:// www.intel- lect-net.com The "rst edition of this book was published about 25 years ago and its various editions have been a popular resource for Book reviews / Biochemical Education 27 (1999) 182 } 189 183