Because the DAFS and XAFS signals have limited photoelectron wavenumber
``bandwidths'', their information content is limited. The number of
independent XAFS points is given by , where
is the filtering window width in *R*-space and is the
window width in *K*-space [24]. For typical values, Å and , the number of independent points
is approximately 10. This is the maximum number of parameters that can
be determined from single shell XAFS data. Note, however, that if there
are *m* inequivalent sites, a set of DAFS measurements for *m* or more
inequivalent reflections can provide up to *m* times as much information as
XAFS. If there are also *p* components in the sample, and each component
has *m* inequivalent sites, then a total of (*pmN*) parameters can be
determined per shell.