Aristotle, one of mankind’s greatest thinkers, rooted his basis of human understanding in the notion that universal phenomena can be explained through perception and rationalization. As such, Aristotle conjectured that a 10-pound object should fall through the air 10 times faster than a similar 1-pound object. This, and other intuitive suppositions of his based on logic, did not stand up to the scientific method.

We now know that understanding natural phenomena requires more than observation and reasoning. Nearly every behavior that exists is subject to variation and fluctuation due to a vast array of influencing forces, many unknown or unrecognized. This variation is further compounded by less than perfect human perception, measurement error, human bias, or just everyday mistakes. The scientific method, traced back to Francis Bacon in the late 16th century, is designed to maximize one’s certainty in the face of the chaos through which one must wade to get to an ultimate truth, and it has become the timetested gold standard by which new entries are added to the human knowledgebase. Even so, the scientific method has itself evolved with its demands for improved signal detectors that better filter out the noise, and in the past 30 years, the role of mathematics and statistics has become recognized as one of the most important vehicles toward that end. Statistics has become like the hammer in a scientist’s toolbox—one of the indispensable tools—especially in the pursuit of new drugs and treatments for human ailments. We present this wholly new updated book in this spirit of scientific investigation and as one additional contribution to complement the many educational resources available to practicing scientists.