  Two quantitative tests DIFF1 and DIFF2 for measuring goodness-of-fit between
two locally-normalized supernova spectra are presented. Locally-normalized
spectra are obtained by dividing a spectrum by the same spectrum smoothed over
a wavelength interval relatively large compared to line features, but
relatively small compared to continuum features. DIFF1 essentially measures the
mean relative difference between the line patterns of locally-normalized
spectra and DIFF2 is DIFF1 minimized by a relative logarithmic wavelength shift
between the spectra: the shift is effectively an artificial relative Doppler
shift. Both DIFF1 and DIFF2 measure the physical similarity of line formation,
and thus of supernovae. DIFF1 puts more weight on overall physical similarity
of the supernovae than DIFF2 because the DIFF2 shift compensates somewhat for
some physical distinction in the supernovae. Both tests are useful in ordering
supernovae into empirical groupings for further analysis. We present some
examples of locally-normalized spectra for Type IIb supernova SN 1993J with
some analysis of these spectra. The UV parts of two of the SN 1993J spectra are
HST spectra that have not been published before. We also give an example of
fitted locally-normalized spectra and, as an example of the utility of DIFF1
and DIFF2, some preliminary statistical results for hydrogen-deficient
core-collapse (HDCC) supernova spectra. This paper makes use of and refers to
material to found at the first author's online supernova spectrum database
SUSPEND (SUpernovae Spectra PENDing further analysis: see
http://www.nhn.ou.edu/~jeffery/astro/sne/spectra/spectra.html)
