Comprehensive and practical guide to using scientific inquiry in conservation work, focusing on the fundamentals of common sense, independent thinking, and natural history. Topics covered include: framing the question and designing the study; interpreting and applying results through judicious use of statistical inference; taking into account the natural history of plants, animals, and landscapes; monitoring and assessing progress through approaches such as "bioindicator species" or "species diversity measures"; and helping other interested parties (park guards, local communities, school teachers) use scientific inquiry in addressing their own concerns.