Chemometrics in Spectroscopy, Second Edition, provides the reader with the methodology crucial to apply chemometrics to real world data. It allows scientists using spectroscopic instruments to find explanations and solutions to their problems when they are confronted with unexpected and unexplained results. Unlike other books on these topics, it explains the root causes of the phenomena that lead to these results. While books on NIR spectroscopy sometimes cover basic chemometrics, they do not mention many of the advanced topics this book discusses. In addition, traditional chemometrics books do not cover spectroscopy to the point of understanding the basis for the underlying phenomena. The second edition has been expanded with 50% more content covering advances in the field that have occurred in the last 10 years, including calibration transfer, units of measure in spectroscopy, principal components, clinical data reporting, classical least squares, regression models, spectral transfer, and more.