ABSTRACT
In near-infrared spectroscopy (NIRS), as we have seen in earlier chapters, one teaches the instrument/computer system what to look for in a given type of sample, then expects the hardware/software combination to produce valid answers when it is presented with unknown samples of the same type. But what kind of answers are we seeking? Usually, they are quantitative answers, in other words, how much of substance XYZ is present in the sample. Occasionally we use what is called discriminant analysis to obtain a qualitative answer, in other words, is this sample A, B, C, or none of these?
