A <a href="search.pl?p=nonparametric test">nonparametric test</a> for <a href="search.pl?p=time-series data">time-series data</a> that detects tendencies for the errors to be in one direction. It can indicate that the <a href="search.pl?p=forecasting model">forecasting model</a> is providing biased forecasts, which may call for changes in the forecasting procedure.<o:p></o:p></P>