TITLE:
ANALYSING CYCLES-in biology & medicine. A practical introduction to circular variables and periodic regression. With stats refresher. MOTIVATION: Cycles surround us. Indeed, they are the essence of life, and critically important in biology and medicine. We need to know how to analyse and understand them. But, too often, researchers are given poor advice: to keep cycles out of data-by restricting sampling to the same time of day, tide, etc. That’s a bad approach; it’s costly because you have to wait for your chosen special times, and even more costly with multiple cycles because you have to wait for even rarer conjunctions of special times (e.g. 1100h and high tide) in each of them. The final consequence is: no matter how carefully you worked, the opportunity to describe key cycles is lost, so your findings are virtually meaningless because they can’t be generalised outside the special times you chose. In fact, it is easier, more useful, and far more beautiful, to put cycles into the analysis than to keep them out of the data. This book shows you how. ABOUT THE BOOK: Written in a welcoming style, the book anticipates readers ranging from apprehensive to advanced. It is copiously illustrated with conceptual diagrams and worked-out examples. It contains all that’s needed to get started: even the basic trigonometry and a crisp stats refresher. All you need is the book, your data, and Excel or a stats package. ABOUT THE AUTHOR: Dr. Bell has his degrees (BSc., MSc., PhD.) from Memorial University of Newfoundland and Dalhousie University in Halifax. He has given courses and seminars in biology, introductory statistics, data management, and science ethics at Memorial University and Rhodes University. His core interests are in aquatic ecology: anadromous gobies, recruitment processes, early life histories, and conservation. He is a strong voice in the role of science in the policy and implementation of fishery management, and a strong proponent of science ethics particularly in government decision-making. He has consistently pointed out the problems that result from secrecy, as argued by the venerable C.P. Snow in Science and Government. He has reviewed for many journals, reported to the House of Commons, and, for COSEWIC (Committee on the Status of Endangered Wildlife in Canada), authored the 1998 Status Report on Atlantic Cod in Canada. That Report resulted in Canada’s first at-risk designation of a commercial marine fish. But that is another story. The author’s interest in circular statistics began with periodic data for which analysis advice was lacking, and he hopes to correct the situation wherein biology is dominated by cycles that are generally ignored, at potentially great cost, because of a lack of knowledge of the proper techniques.
