Predicting what occurred in a time period prior to the period used in the analysis. Sometimes called postdiction, that is, predicting backward in time. It can be used to test predictive validity. Also, backcasting can be used to establish starting values for <a href="search.pl?p=extrapolation">extrapolation</a> by applying the forecasting method to the series starting from the latest period of the <a href="search.pl?p=calibration">calibration</a> data and going to the beginning of these data. See Armstrong 
 (2001d).</P>
 <ul>
   <li>Armstrong, J. S. (2001d), “Evaluating forecasting 
methods,” in J. S. Armstrong (ed.), <I>Principles of Forecasting.</I> Norwell, 
MA: Kluwer Academic Press.</li>
 </ul>