A method for programming data into a first plurality of rows within a second plurality of erase sectors of a flash memory device using a programming process having at least one selectable parameter, the method includes characterizing each of at least one row subsets, each row subset comprising at least one row from among said first plurality of rows, thereby to generate at least one row subset characteristic value; and programming data into at least a portion of at least one individual row belonging to at least one row subset, using a programming process having at least one selectable parameter, said at least one selectable parameter being set at least partly in accordance with the row subset characteristic value characterizing a row subset to which said individual row belongs; wherein at least two row subsets of an array of flash memory cells differ from each other by their row subset characteristic values.