question: private boolean isModelUseful ( ContingencyMatrix cm ) { for ( int row = 0 ; row < cm . getNumberOfPredictions ( ) ; row ++ ) { for ( int col = 0 ; col < cm . getNumberOfClasses ( ) ; col ++ ) { if ( Math . abs ( cm . getLift ( row , col ) - 1 ) > MIN_ADVANTAGE ) { return true ; } } } return false ; }
target:  Helper method to decide whether a model improves the training error enough to be considered.