This volume brings together three seminal works by the late R.A. Fisher, whose writings have had more influence on statistical theory and practice than any other 20th century statistician. It includes Statistical Methods for Research Workers, Statistical Methods and Scientific Inference, and The Design of Experiments, all republished in their entirety, with only minor corrections. An informative foreword by Dr. F. Yates, one of the author's closest colleagues and collaborators, discusses the key issues found in the texts, shedding new light on how Fisher's ideas have become mainstays of modern statistical practice.