Methods of reducing the effects of measurement device artifacts on a
measurement of a sample are presented. A number of reference measurements
performed with the measurement device are observed to identify reference
independent components of the reference measurements. The variations of
the reference independent components are used as surrogates for possible
artifacts of the measurement device. A number of measurements of subjects
similar to the sample are observed, and similarity components of the
subject measurements that vary in a manner similar to the reference
independent components may be identified. The sample measurement is then
adjusted to remove at least part of the similarity components that
correspond to the variations in the reference independent components. The
adjustment of the sample measurement is thereby improved by reducing the
effects of artifacts of the measurement device.