For each sample, the indexed peaks were used to determine a trial lattice parameter for each
peak. Noting that Equation (1) predicts greater experimental precision with higher angle, these
higher-angle peaks should be given greater weight in determining the lattice constant. One way
of accomplishing this is by “reducing the data;” correlating calculated a constants against a function
which predicts expected precision. In a thorough examination of error, Nelson and Riley[5]
determined that the relation