In processing the test spectrum, background reduction, normalization and alignment of the test spectrum may be performed to better match the test spectrum with {HEAD ~ the group} of {TAIL ~ class labeled spectra}, which have been processed in the same or similar manner 
of
In processing the test spectrum , background reduction , normalization and alignment of the test spectrum may be performed to better match the test spectrum with { HEAD ~ the group } of { TAIL ~ class labeled spectra } , which have been processed in the same or similar manner
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH