You are working with the text-only light edition of "H.Lohninger: Teach/Me Data Analysis, Springer-Verlag, Berlin-New York-Tokyo, 1999. ISBN 3-540-14743-8". Click here for further information.


Whenever some measurements are taken, one has to deal with variability (or dispersion) in the data. As a matter of fact, virtually all natural processes vary - even those which yield "constant" results show up fluctuations if either the observation time is long enough or the scale of the measurement is zoomed in.


Statistics helps in coping with situations in the presence of variability. The reason for the variability may be twofold:

The variability in the data is often referred to as the noise that obscures the true signal.

Last Update: 2004-Jul-03