1. A method for selecting at least one steel grade from a stock of data, stored in a non-transitory memory, for a population of a plurality of steel grades using a data processing device, having the following steps implemented by the data processing device: a) displaying a selection device ( 11 ) which can be operated by a user on a display means ( 12 ) that can be used to set values for at least two steel grade features which respectively denote the steel grades; b) displaying of the population of the plurality of steel grades at least in part on the display means ( 12 ), wherein the selection device ( 11 ) is at least intermittently displayed together with the population on the display means; c) querying the stock of data for a steel grade for which the stock of data stores values for steel grade features which correspond to the set values of the steel grade features or which fulfill conditions which are dependent on the set values; d) if the data processing device determines that said query is satisfied by at least one steel grade and in so far as said at least one steel grade fulfills at least one further condition, displaying said at least one steel grade or information representing said at least one steel grade on the display means ( 12 ); e) highlighting the at least one steel grade satisfying the query against the displayed steel grades from the population which do not satisfy the query, and identifying at least one steel grade as satisfying the query; and f) after a change of values for the steel grade feature, performing the query again by operating the selection device ( 11 ) using the updated values and displaying on the display means ( 12 ) a steel grade that satisfies the query, and/or fulfills the at least one further condition, and highlighting the steel grade against the displayed steel grade from the population which does not satisfy the query, wherein the steel grade highlighted against the rest of the steel grades before the values are updated is not highlighted on the display means ( 12 ) again, so that the steel grade is no longer identified as having been selected, in so far as the steel grade no longer satisfies the query after the values of the steel grade features have been updated.